I travel to various wild fires and I sleep in the back of my 04 4Runner and I got a generic twin bed air mattress and the length is just right but will sleep only 1. I got mine at an outdoor store but you can look at the large box stores. An additional item you might want to get is the wind and rain deflectors, for at least your rear windows. These are the hard plastic window covers that mount on the exterior of the doors, above the top of the windows and allows you to open the windows an couple of inches and prevents the rain from entering the interior of the vehicle. This is important to help regulate the moist, given off by your body, in your vehicle as you sleep.