Usually I've found BMW AUCs OK, as said you do need to give the car a thorough going over, however I've found any minor probs the dealer has sorted before delivery with no issues. Depends on the dealer at the end of the day but found mine spot on, even painted the rusty hubs on my old 1 Series and touched in the odd stone chips in the body shop.
I feel you would have more recourse from a franchised dealer than a non franchise. Still alot of readies should the car be a lemon and the non franchise dealer doesn't want to know.
Tim.
