What type of rear axle did the AWD Caravans have in them? That does sound like an interesting concept. I would love to build a mid-engine rig, but I'm concerned with having enough room for a good pinion angle. If I set the engine/trans in back of the front seats, that doesn't leave much room for a driveshaft, if any. A 3 inch driveshaft doesn't make for very good angles or allow for rearend movement.