When Automobile got their paws on a six-speed manual version of the M5, they were none to pleased that BMW's engineers wouldn't allow drivers to fully disable the traction control. At the time, we assumed that BMW's legal boffins pictured overly enthusiastic Americans, stomping the go pedal and promptly winding up in a ditch.

Not so, according to Car. The magazine learned that the M division had no way of controlling clutch plate actuation, which would normally quell the axle tramp caused by the V10's prodigious power delivery. Acceleration times would rise and drivetrain components' lifetimes would fall. Hence, the only conceivable solution was to make the DSC a permanent fixture within the Bimmer's brain.

Still, you can partly disable the system in M Dynamic mode within iDrive (if you dare), but that may not be enough for those who want to test the limits of adhesion of the 285s in the rear.

http://www.carmagazine.co.uk/news.php?sid=421&page=1