This mattress opened up new camping and travel opportunities for me and my son. Even in the summer here in CO, at over 10k feet elevation it can be hot during the day and near freezing overnight. Winter camp in subfreezing temps is much more enjoyable. In the car it's always a great temp for sleeping and moisture is controlled. High winds or rain that pop up overnight are no problem from inside the car. Setting up and breaking down camp is far faster eliminating the tent and if it's wet in the morning, so issues with trying to dry a tent before packing it up.
I've used the mattress now on several trips and would buy it again. It's very comfortable to sleep on. Since its memory foam, it's not bouncy like an air mattress that just uses air for support. The thickness, at 4.5 inches, helps mitigate the slight incline of the folded back seats. Its self-inflating and doesn't really need a pump to reach a good firmness, but definitely requires a pump to get as much air out as possible to roll it up. I made an adapter for an inflator/deflator that I bring camping as its good for other things like inflating watercraft and blowing dirt/debris away. It goes door handle to door handle and hatch door to back of front seats, so stuff doesn't fall. It doesn't cover the rear side storage bins, which is the perfect place to put shoes/jacket/flashlight for getting out of the car overnight for the restroom.
Rolled up it just fits in the underfloor storage or the frunk and it's a bit of a struggle the first couple of times. Strong hands and dexterity needed. I suppose you can choose thinner mattress of the same type (memory foam), which is easier to roll up, or a thicker mattress that is more comfortable. If comfort is the priority, this is a great mattress for the Y.