I have learned the hard way - there's not much difference between car and RV dealerships. Try to get the customer to pay before they tell you it's covered.
If there is an access panel, door or hatch open it and check for problems. If there is a roof ladder climb it and check for even sealant beads, caps and rips. I missed window sealant - the whole back end had to be replaced because of water damage, still missing inside molding and shelves aren't level. The furnace gas hose was kinked, no heat in October.
Even though we had the post purchase demo, we should have done a preinspection. We were left with the feeling missed sealant and the kinked furnace hose has our slip up. Bad taste after spending over 35K.
At least we took lots of pics before and during our purchase negotiations. The dealer knew it wasn't right to begin with.