Question for those of you with the pop out campers (the ends that pop out and you sleep in them). What do you do for mattresses?

Ours came with super thick foam mattresses that were too big to stay on the wooden pull out when it was packed up, and when they were slept on, our bodies made indentations in them. We've gotten rid of those and are currently using blow up mattresses, but it's not ideal. DH split one with his elbow the other day and I'm experiencing a fair amount of hip pain during the night as the air filters out gradually. Any tips or suggestions as to what you're using?