It was suggested I share here my little mobile bedroom i’m working on. My Toyota Yaris turned “YarV”.

Foam roll-up camping mattress(never have to re-inflate in the middle of the night!) : https://www.amazon.com/dp/B07TGDP6PP?ref=ppx_pop_mob_ap_share

Behind seat storage/mattress support: https://www.amazon.com/dp/B07KQX12V7?ref=ppx_pop_mob_ap_share

Thanks! It comes in a few different sizes, the one I got is 75 in long

https://www.amazon.com/dp/B07TGDP6PP?ref=ppx_pop_mob_ap_share

A twin foam mattress will be fine for one person. I bought and used this one. $130

CertiPUR-US Memory Foam Camping... https://www.amazon.com/dp/B07TGDP6PP