Used to own one of these things... had an APR pulley, chip and intake and it was a lot of fun. Took a Mercedes C400, C450 amd C43 for a rip when I worked for Benz and it was a far superior car!!! I would take the c class over an S4 any day. Both are Great cars but the c400 handled and drove better and the interior quality was far superior. Lots of C400 coming of lease now for decent CPO deals!