GRA wrote:FWIW, I've been using a 20" x 72" x 1.5" Thermarest pad in my Forester for years, as well as for the ski-camping and shorter backpacking trips where weight isn't critical that I bought it for. For a pure car and car camping pad I'd probably want a wider one, but I'm too cheap to spend the money when what I have works. Going longer than 72" can be problematic depending on the car; most of the wider pads are 77" long, so check first.
It provides plenty of cushioning. It all depends on what you're used to - for summer backpacking trips I routinely sleep on a 20" x 48" closed cell foam pad, although I wouldn't choose to use something like that in the car when weight and bulk aren't an issue.
I also have the 1.5 in thermarest. What bugs me about it is when I sleep I tend to roll around from flat on my back to my side. The parts of my body, knees/feet/backside tend to slide off the pad enough to where I notice it and it bothers my sleep. I am not a big guy, 5'8", 145lbs. This is why I bought the prementioned pad 30in-er. However if I had to do this again
I would buy the equivalent 25in-er. I think the 25in may allow me to sleep with one of the back seats still in place, creating an extra place to put stuff.
My 1.5in Thermarest also balloons around depending on how my weight shifts which is also bothersome. But the 4" thick one I have now... NICE! Was the most comfortable I have been on ever. In retrospect though I think the 25in one may present more options in the leaf.