why cant you do the work on an M5 or any car your self? its only nuts and bolts, same as a cosworth.
An M5 @ 100K is just loosening up, making its full potential, the same with alot of modern machinary
Agreed, in fact, im sure every tuner will agree, the M5 is FAR FAR easier to work on than ANY of the Cosworth range. The E39 is renowned for its over engineered simplicity.