I really don't have "THE" Taj Mahal...just the mini So Cal one...
(Thanks Mikey, and weren't you one of those partaking of the bubbly sittin' on the back couch?!
Take it from someone who has has both a garage and a big living area in the same rig...when we got our earlier SLC3705, I said I'd never have a sand car, so my high desert friends (who are framers) built this beautiful garage wall complete with door and windows. Completely trimmed in, newly carpeted living area- all you would've wanted. You should have seen them cry when I had to tear it out 5 months later when I traded my XR250 for a high jumper. That's when I put in the french doors on the back because we liked to keep the a/c air IN and the dust OUT...
Ther are things you can do to minimize the smell you get from having bikes and autos in the living area. Our biggest was tying all the vent tubes together with 1/4" drip tubing and venting them out of the coach- helped a bunch. Then simple tarps on the floor for the sandcar kept anything off the carpet we had.
Personally, I wouldn't have a garage, but as Mikey said, opinions are numerous. Just don't go overboard until you have a chance to settle into your niche!