Well the dealer put the car up on the lift yesterday and found some problems. It seems as though there is a rust problem on/in the quarter and rocker panels, he says that the subframe appears to be okay. Problem is it looks like someone attempted to fix it and just compounded the problem. Still going to go up and take a look myself, the dealer guesses whoever owned the car parked it on the grass for quite some time.
This sucks. I knew a 73000 mile M3 was too good to be true, but now i have an excuse to look for an Imola Red one.