This is a huge issue out there. I see it all the time. Huge camper/trailer on a 1500 or 2500 truck, and the tail is wagging the dog. Unless a few RV dealers start getting pulled into lawsuits where an overloaded truck with camper or trailer is involved, the sales people will continue to sell the biggest (spelled $$$$$$) rig they can. Depending on where you are, many jurisdictions in North America can scale anything, including an RV, provided the GVW is over 10,000 pounds, not the registered or actual weight, the rated weight is what determines this. The GVW is determined by the engine, transmission, chassis (frame, springs, axles, brakes), and tires. If you exceed what the manufacture states is the maximum safe weight for that vehicle, you may be completely liable in a collision. Know what you can safely carry before you make any RV purchase, or buy the right hauler for what you want. It could be the difference between life and death.