The tri-fold mattress I purchase when I 1st started driving around the country, worked for a while but eventually I needed something a little thicker.
During my trip to Big Ben in Texas I ended up finding a 2″ mattress topper and I believe it was for a full mattress, I just put that inside of my prius then put the tri-fold mattress on top of it.
I also purchased heavy-duty scissors so I could cut off a portion of the excess mattress topper, they didn’t work well. Eventually, I purchased a foam cutter and now I wish I made that purchase sooner!

For me, two mattress toppers weren’t enough, adding the tri-fold mattress is what really made for a comfy sleep!