Hi KC,
Roughly 1/3 of all motorhomes are marketed that way because the RV manufactures release their model year about 5 months prior to the chassis manufacture. So there is huge amount of production time where they mismatch. Complicating the matter is chassis overstock. During the great recession of 2008-2010, some motorhomes were two years apart. You would see a 2010 motorhome built on a 2008 chassis.
Our first motorhome bought new, was a 1984 built on a 1983 chassis. I knew about it up front but later regretted the decision not to wait for a match. There was always confusion when it came time for emissions testing and insurance. Also it never felt right until enough years passed by and didn't bother me anymore. We owned that rig for 24 years.
When ordering our new rig in March 2007, I made sure the chassis year matched the RV model year. The RV manufacture actually built the house on a freshly made E350 chassis such that they were only a month apart in age. That was in April/May of 2007. Had I placed my order a month or two later, my RV would have been a 2008 with the chassis being a 2007. Some people would say it would have been better to wait. That never crossed my mind at the time, but am happy to have matching model years for a change.
