Here's the deal on the propane. Basically any RV manufacturer that installers propane is taking on some big risk, and they need more insurance. Thus my understanding is the the Snoozy folks don't want that risk nor paying for the insurance. Nearly every RV out there has propane installed in it, so saying it's dangerous is just crazy talk.
12' Toy Hauler is a bit of a oxymoron. The vast majority of folks want a 12' garage not a 12' unit. You might want to check out the Airstream Basecamp units they run 16' but they come with propane.
