This is exactly the place for this kind of discussion. General prep and project questions would go here, and once you have a specific mutant vehicle plan to announce for a year's event, you'd post that in the mutant vehicle board (for announcements and updates and whatnot).
Domes on trucks and buses have been done a few different ways over the year - the most elaborate version I can think of is the Death Star Art Car - that team of awesome people didn't just build a geo-dome, they built the whole damned sphere! We had the pleasure of being camped a block or two away back in 2011, and had a decent view of their on-playa assembly as we put our own camp together before the gates opened up. They had use of a piece of heavy machinery to lift the dome as they went - once they had the entire sphere in place, it was raised up into place and then secured to the top of the vehicle.
Don't let the fact that others have done something similar before stop you - nobody's probably done what you're dreaming about, and even if they have, they haven't done it your way. Besides, it's a big-ass playa, there's room a couple of anything.
Actually, since we were busy with our own stuff I didn't get to see all the details - I'm not sure if they ran their lighting as they built it, or if they had people climbing up on the completed sphere once it was in place.
One thing to mention... if you're planning on embarking on this adventure in 2014, hurry up and get your plans together - the
mutant vehicle applications close on May 15 at noon!.