car camping: inconspicuous + insulating window covers

I'm planning some extended car-camping road trips and am looking for some window covers for privacy + insulation. I've used reflectix in the past and that makes it pretty obvious that someone's sleeping in the car. Any recommendations for something that fits the bill but basically looks black from the outside instead? Anything better than just cutting and spray-painting some reflectix?

I bought a roll of Thinsulate insulation (600?) series that is about 1.7" thick and picked up some deep black fabric (outside) and some lighter colored fabric for the inside and hand sewed it together. I used cardboard for a pattern. Depends on how bulky you want it vs. insulation value. 

I use reflectix but with black felt glued to one side with 3M Super 77 spray glue. From the outside, the windows look completely blacked out.

Weather Tech makes sunshades that are black on one side, reflective on the other, that are designed for specific vehicles. Good for privacy, prevents heat buildup in summer, avoids the home made look that tells people someone is sleeping in the vehicle. Even the black side wouldn't add too much insulation in winter, though. weathertech.com/sunshade/#

https://www.google.com/search?q=thinsulate+sm600l
An excellent van insulation that you can just spray adhesive the walls and apply the white side directly. You could spray adhesive on black felt or fabric to the white side and use this... but it will be bulky and you will need to figure out your own mounting system. I think CD Transporter's idea should work well as long as your felt doesn't let in light to bounce off the reflectix. Good blackout specific fabric probably wise. You will have to figure out mounting.

Reflectix that's spray painted black on one side. 

mark felber wrote:

Weather Tech makes sunshades that are black on one side, reflective on the other, that are designed for specific vehicles. Good for privacy, prevents heat buildup in summer, avoids the home made look that tells people someone is sleeping in the vehicle. Even the black side wouldn't add too much insulation in winter, though. weathertech.com/sunshade/#

I have the WeatherTech window covers for my Subaru, have had them for ~2.5 years, and I think they are really great. Excellent sun protection, and there is definitely a noticeable difference in warmth on cold nights when the shades are up, but I’ve only camped in my car when the weather was down to low 20s at night, not any colder than that. 

Thanks everyone this has been super helpful!

The WeatherTech are one of the best birthday gifts I’ve ever received (thanks pops!), *hypothetically* one could park in front of fancy hotels near 5 star climbs, in front of 3000’ granite monoliths, and even downtown Telluride, and nobody would notice, let alone bother you.
they have been an absolute game changer for me, though you will want to back up the windshield with large tri-fold squared oval windshield blockers, and also may need to use the adhesive backed Velcro in strategic locations to ensure the weathertechs don’t slip out of place. Enjoy your newfound freedom