You need to read up on Hantavirus
CDC link to vehicle cleaning . Never vacuum mouse droppings without soaking with bleach solution and waiting at least 5 minutes. The exhaust of the vacuum puts the virus up into the air. The link has some good info/precaustions on cleaning a vehicle as well as where to look.
In a RV I would look under all the cabinets, the power panel area, vent ducts, storage compartments, propane and battery compartments, etc. etc. Those are all places I have found rodents trying to nest.
It is not a trivial job to clean a RV with a rodent infestation.