Behind the front seat for sure. I have a black out curtain that snaps to the over head just behind the seats. It's long enough to also snap over the side windows and the windshield. I use it behind the seats 90% of the time since it's quick, easy and sorta stealth, looking a bit less like someone is living inside. It's hard to make it completely "light proof" though, so when urban camping I park under the brightest light I can find, so interior lights don't show as much. For winter camping, a well insulated curtain would be even better. There is a fabric called "warm windows" I considered making some out of, but it's darn expensive, so I went with some blackout curtains from Walmart for a start. With winter on it's way though, I'm beginning to think about an insulated set. Make it black on the side people see from the outside, well insulated, and also make it so light doesn't show from inside and I'll buy your first set. Additional inserts for the windows in back will also reduce the heat loss, and work better than the Reflectix I use now.
Agile Ride improvement package