You don't state where you live or purchased the RV. NO, it is not normal on a new RV. Go to your RV on the outside usually the Left front sidewall. There will be VIN sticker listing the VIN and weights and such. On that sticker will be the Month/year RV was built. Post the results once you find it. Dealers are supposed to wash all undercarriages of RV's when they are delivered during the Winter months from the OEM's which the majority are built in Northern Indiana. The washing is supposed to remove all road salt and chemicals used by hi way crews in icy conditions. Almost ALL OEM's send out bulletins to their dealers in the early fall to remind them to wash the undercarriage of all incoming new RV's. We have a washer system we drive the units over to rinse the undercarriage's. The rust is really unsightly surface rust and should cause no problems. But, it should not be there regardless. Bad news is this, the OEM will NOT warranty this problem as it is the fault of the Dealer who failed to follow the OEM's guidelines. Dealers do not have to wash units that come in on LOW BOY trailers. This is only for RV's that are transported rolling on the ground. Doug