Hi! My 2400/Sprinter has two leather couches. I sleep on one with a bed in a bag set that
was bought at Camping World. I usually keep a cover (a washable quilt from Target) on the couches because of doggie toenails.
At night, that stays on and then I unroll the foam egg crate type topper and put it on the cover.
After that, I sometimes lay a sheet---but next the bedroll/sleeping bag.
The couches sleep much better with the foam layer. In fact, very well.
I roll up the foam pad and store it in a mesh laundry bag
from WalMart....and the bed bag is rolled up and stored in a cloth bag.
I found inexpensive foam pads during college shopping sales. Lots of stuff is out then and fairly cheap.
Don't recall much slippage.