Cruise around in the desert long enough and you'll see about everything. 4 door long box 4X4 pickups with no lift, Ford Taurus car, Jeeps of every description, Nissan Versa Note, Lots of side by sides, a few dirt bikes, some quads. The thing that quads and bikes have going against them in this area is they're both tough on the riders, and old guys, which there are plenty of here, probably would not bounce back from the punishment they are capable of meting out. A coil over shock that is coupled to a trailing arm suspension is what the million dollar trophy trucks use for off road racing. Same suspension is used in the RZR XP models because it soaks up the bumps better than anything they have come up with so far. Jay in WA said it best, Just about anything will get you there but some rigs will take you a lot longer to get there. 
Last season, I got talked in to leading a good sized group. Some nice rigs driven by experienced drivers and some not so nice, driven by rookies. You have an idea the pace is way slow when an 80+ year old lady says she's not going with the bunch any more because they go way too slow ;-)