Originally Posted by bigfelipe
So who knows what this subfloor material is? Anyone?
Probably only someone who's got your exact model and has removed the carpet as you have would know. My Airstream (on a Chevy chassis) has either 5/8" or 3/4" plywood.
Maybe you can look under one of the rear seats where a hole was drilled when Roadtrek installed original wiring or plumbing. Just don't remove any sealant which would make an opening (unless you seal it back) and make sure all ac power, generator, inverter etc. are off when you're in there.
Ultimately you must decide if you can go over what you have, or remove it until you reach the base subfloor. Then you need to determine how thick your sub-flooring is and don't drive any nails/screws/staples deeper than it because you won't know what lies below.