Not that I've ever seen.. Once past the 2 front seats, you might see belts on the couch that's up front, but pretty much, in MH and Limo's anything past the 2 front seats is just like a "bus".. Heck, you can have open containers in the rear part of MH and limos as long as it's all "personal" transportation.
Do public buses or even school buses have seat belts?
What you are looking for is one of those 12 passenger vans that have belts for every passenger.. Then tow a nice TT to be your "house"..
Good luck!
Mitch
