Make The Best Privacy Window Covers – Complete Guide

Privacy was probably my number one concern when considering living out of my car. I didn’t want anyone to be able to look through my windows and see me lying in there, for reasons of safety and of not being caught and asked to leave wherever I was parked. I also didn’t want to be woken up by excess light coming from passing cars or even the rising sun. So all together, I needed privacy window covers that blocked out all light, were easy to setup, simple to store, and were difficult for anyone outside to know they were in place. And that’s exactly what I made!

In this post I’ll discuss in detail what I made, how I did it, some problems I had, and what I did to solve them. Of everything I’ve learned about sleeping in a car, these privacy window covers are probably the thing I’m most excited to share since I think it’s so important and so equally overlooked. Let’s get started!

The Idea

I had a general idea of what I wanted to make. I knew I was going to use a material called Reflectix (basically a metallic bubble-wrap used in housing insulation, Here’s a link to the one I bought) and I would wrap the Reflectix in some kind of fabric to make it more appealing to look at from the inside and indistinguishable from the window from the outside. I was planning to use a spray adhesive like 3M’s Super 77 (Amazon Link), but I wasn’t sure how to affix the edges of the fabric, either sewing them or using two layers of Reflectix and trapping the raw edges between the two panels. Besides figuring these details out, I had some other concerns.

The Problem with Reflectix

As an engineer, I had to look at all of these materials to see if they would work for my application. I wanted to use Reflectix because it’s what everyone else was using to insulate their vans and car campers. But, I found that it’s actually not very good for this application.

Reflectix is a composite insulation system usually used in basement ceilings and between roof trusses. It only has an insulative “R” value when it is allowed to have an air gap between two panels of the material. This trapped air is how the insulation works. In our application as vehicle dwellers, placing this right up against the hot metal walls of a van or against a window, it only acts as a radiation barrier and doesn’t actually do much to prevent heat from passing right through from either side.

That all being said, I couldn’t think of another material rigid and yet flexible for pushing these into the window sills of my car and then storing them. I could have used foam board, but those would have broken after a few uses and any other rigid material wouldn’t contour to the window’s curves. So even though I knew I wouldn’t get as much insulation as I could from this material, I continued to use Reflectix through this project.

Prototyping

Okay, with all that planning stuffs for these privacy window covers out of the way, my first step was to go out to my car and make paper templates of the windows. I happen to have a giant roll of brown paper which made this easy, but you could use poster board, flattened out paper shopping bags, or piecemeal printer paper. The goal is to get an accurate template of each window shape in the car. And since the two door and back side windows are symmetric I only had to take one template of each.

If you look closely, you might notice that I didn’t take a template of the front windshield. This was intentional. I already have a reflective cover for my windshield, and so I didn’t feel the need to make my own. And more importantly, people expect to see those kinds of window covers already, it would be strange to see a cars entire front window blacked out by my privacy window cover.

Anyway, now it was time to buy all of the material. I used the paper templates to measure the size of fabric I would need to cover the pieces and headed over to JoAnn Fabrics. Originally, I wanted to purchase felt because it would have great light absorbing properties, and I still think it would be a great choice. But, JoAnn’s had some fleece on sale at the time for about half the price of the felt. I purchased a couple yards of black (for the outward facing side) and an equal amount of white (for the inside).

Before I started making all the covers, I wanted to test out my idea. So, I took the smallest window template in the car and cut out a few Reflectix panels that matched the template, and then cut out each fabric color with about an inch of overlap. Then came the trial and error part…

Remember how I said I wanted to sew these? Well I actually tried it. Wrapped the fabric around a single layer of Reflectix and tucked the edges of the white fabric and placed that on top of the open edges of black fabric and the exposed Reflectix. If your keeping score, that’s now four layers of heavy fleece and a layer of Reflectix. Which my sewing machine didn’t want anything to do with. The stack was way to thick and too squishy to be moved through the feed-dogs of my machine. So, I had to scrap that idea and moved to plan B.

Taking two layers of reflectix now, I used the Super 77 spray adhesive to attach the fabric to each separate piece of Reflectix. Then, I again used the spray adhesive to attach the two panels together, trapping the raw edges of the fabric between the panels. This looked much cleaner and was surprisingly sturdy, not feeling like it would fall apart.

Now with one finished, I couldn’t help myself from taking it out to my car and popping it into the window to see how it looked.

The interior looked really nice with the white fabric. It made the space feel a bit more roomy having those in there opposed to a darker color. And the cover did a great job of wedging into the window sill and didn’t need any other help staying put.  The picture below requires a bit of explaining to know how awesome it is!

I have all my lights on in the car and they are pretty bright. You can see into the car through the back door window, and directly to the right of that is the window with the cover in it. That big piece of black, the the right of the image, framed by the red metal skin of the car should be as see through as the other window in the shot, but it’s not! It actually took me a second to realize where I had put up the test privacy window cover, because it worked so well in preventing light in or out.

The only way to tell it was there was to shine a flashlight directly into the window and look closely to see the fabric behind the glass. Barring that, it was completely undetectable. With this success in and, I continued with the rest of the covers!

Production

Using the paper templates I took earlier, I cut out two panels of Reflectix per window. One tip that I can give if you want to use this same construction, orient the creases in the Reflectix to be perpendicular in each panel. Because this material is sold rolled up, there are creases and folds that can’t be removed. If you cut your pieces so that these creases are 90° apart from eachother it will yield a much more rigid panel. The careful reader will notice that I failed to do this, so definitely listen to Lucas of the future on this one!

It was also important to stay organized since all the panels looked similar and could have easily become mixed when proceeding to cover each panel in fabric. Above you can see me using a Sharpie to denote inside/outside layers and right/left side for the the applicable panels.

I was really glad to have taken all of these cutouts to my car for a dry fit. Almost all of them didn’t fit properly, and with the help of my scissors I reshaped them all to best fit the windows, keeping in mind that the fabric would also add some interference between the covers and the window frames.

While I was down at the car, I also took note of the covers that were directly contacting a steel door frame. On these sides I planned to add magnets to better hold in the covers.

With all the planning accomplished, I began the long process of tracing all the panels onto the fabric leaving about a 1 inch of allowance to be wrapped around the edge of the Reflectix.

With all the fabric cut out, I started the process of attaching it to the Reflectix using the Super 77 spray adhesive (Amazon Link). I placed small rare earth magnets (like these: Amazon Link) on the edges of the Reflectix and folded over the fabric edges using scissors to make small cuts around the curves and corners allowing the fabric to sit flat. I was very careful to note which panel of each pair went on the outside and which went on the inside. Because, when I cut the Reflectix to match the car during the dry fit, it made all the panels slightly different.

Marking with a Sharpie the location of each panel was very helpful, just make sure not to put markings on the side where the white fabric is attached. The black on silver shows right through and I had to disassemble some of the panels to clean this up.

With the fabric attached on both halves of each panel, I used the same spray adhesive to join the halves, making sure all the edges lined up. The Super 77 spray adhesive is a contact cement, so make sure to let the two sides dry a little before pushing them together.

Testing

As soon as I finished all the panels I ran down to the car and pushed them all into place. They were very easy to locate since they all could only go in one way now with the black sides facing outwards and the white sides facing inwards. I took a video of the results as seen below:

I was sitting in my car in the middle of the day. Those touch lights are not very bright, but because the window covers blocked out all the light, they were needed to see inside the car! You can really see the effectiveness of the when I open the door. I have my regular reflective front window cover up, and its light seal isn’t as good as the covers I made.

Shortly after I finished the window covers, I set up the sleeping space in the car and went to sleep in the parking lot of my apartment to test out some of my systems. I learned a lot from that simple test!

It proved to me that the window covers blocked out a lot of light that would have kept me awake. They also isolated me from some of the road noise and foot traffic outside my vehicle. The black fabric also worked perfectly and the car looked like any other parked car in the apartment lot. And some more icing on the cake, the fleece fabric of the covers absorbed excess moisture and prevented the windows from fogging! This would also mean I would have to make sure they could dry, or I would risk molding (this never became a problem). However, even though the window covers were exceptional at blocking out everything I wanted, I quickly realized that they also blocked out the air.

First Problem

I had all my windows cracked open as far as they could go and still be covered by the rain guards on my car. I initially though that air would seep through the edges of the window covers and that would allow circulation, but air is much lazier than that. In my test, I bent the top edge of the window covers down to open the interior of the car to the outside air. But, the semi-rigid stacks of Reflectix and fabric always bounced back into a flat sheet. I wanted to still be able to press the window covers in flat to block out all light, but I needed a way to hold the top edges down while I slept.

My solution was to use some thick armature wire (Amazon Link) to build an internal, bendable structure in each panel that was over an opening window. Below you can see the type of wire I’m talking about. It’s very pliable and can be bent over and over again without breaking.

I arranged the wire in a zig-zag pattern of roughly four inch by five inch rectangles all the way along the length of the panel where the window opened.

I simply pealed apart the two halves of each window cover, and then placed in the wire, and used some more spray adhesive to join everything back together.

The finished covers would now bend and stay in place, letting is as much air as I wanted!

Having the tops of the window covers not be in contact with the car window frames made some of them not want to stay in place. This made them a little more finicky to setup (especially when opening and closing doors) than I would have liked, but I got the hang of it after a little while.

Some More Problems

I was staying with some family right before I left on my trip to Maine. We had a chance to go camping and I thought it would be a good opportunity to have another test of the car. At the time everything was loaded in that I would be taking with me. Right away, I noticed a fairly big problem. Having all the window covers bent to let in air worked really great, but they also created huge entrances for bugs. This completely escaped my mind, and would be a major problem in the mosquito infested state I would be heading to.

So I improvised a solution, adding store bought fabric tulle, framed it with way to expensive velcro, and added the assemble to the tops of the window covers. The idea was to fold open the window cover and attach the netting around the opening. The headliner in my car could be used as the loop side of the velcro.

This was a good short term fix, but the modification had so many problems I won’t bother to show the construction. The tulle was way too weak, the velcro started to tear up my headliner, and the covers would fall out of the frames when I opened a doors because they were attached to the ceiling. They did keep bugs out of the car, but let in more and more as the netting wore.

Another annoyance I found well into the trip, was if I left the covers up for an extended period, the Reflectix would loose its rigidity. So the covers would just fall out or have trouble just going up. I had to take them down regularly and massage the edges of the window covers to flatten out the Reflectix to make them fit again.

Future Improvements

Even with all the above problems, I still think these privacy window covers suited me very well, and continue to with some adjustments. The black fabric was more effective than I could have ever imagined. Also, I now know that I can get plenty of airflow from just four cracked windows, even in a southern summer. I’m working on making a much better version of these privacy window covers, and producing plans on how to make them for any vehicle, so watch out for that!

Did I miss something? Do you have a better solution to cover your windows? I’d love to hear your questions and comments on this content below!