Ok I know this forum is probably just a touch biased, but I'd like to ask the opinions of some people experienced with the cars I'm currently interested in. I am thinking a (all of these used) 850Ci Steptronic or 6sp, 540i Steptronic, Porsche 993 C4 Stick, 850CSi (obviously stick). I'm not so much concerned with the cars as I am with maintenance costs. I have always loved the looks of the E31 but I'm worried for the maintenance costs for the big V-12, especially on the CSi. Is it going to be outrageously high when compared to the 540 or 993? Are they more prone to problems than the 540?