We had a the full size Navion 24J and took it to Wagner BMW in Shrewsbury, MA.
It fit in their facility and they treated us well. Unit was under warranty at the time.
NOTE: They don't do a lot of motorhomes. Customers, mechanics, and salespeople all had to come out and look when we dropped it off.
It also took them a while to find the info in their system that confirmed it was still under warranty.
Good Luck with your Navion... We loved the fuel mileage
Norm & Ellen
2007 HR Ambassador 40SKT
2008 Mini Convertible following close behind