Mike, welcome to irv2
If you plan on buying a good to you TT check all compartment openings look for stained interior carpets, look for wall paper peeling around windows, stains in ceiling fabric around vent openings or AC's.
Check plumbing in water compartments,under
sinks,bath,kitchen for leaks just remember any water leak, however small, can be many feet from the actual leak entrance point.
While your at it check all windows for sealents,roof vent openings on roof, refer and furnace openings for sealents also.
You will want to check all these items before passing check, than you will know if something is amiss, you know the dealer corrected what you did find to be fixed. Good luck hunting, an have fun in the RV world,we are here to help in any future questions.