>>1384679foam>>>>air mattress
>more comfy>less affected by other person's movement>can cut it to fit just right>don't have to fill it up>don't have to worry about it losing air over nightjust be sure to order it with enough time to let it air out for 24-48 hours so your car doesn't smell like a chemical plant. my wife got the "Zinus 4 Inch Green Tea Memory Foam Mattress Topper, Twin" off amazon for car camping while she's pregnant. i thought she was bonkers and it would be too thick, but it was comfy as fuck.