They may have taken the Red Rocker reference we were almost bound by Jalopnik charter to make, but the boys at Bavarian Falcon found the item first, so we've got no blogethical right to it. Nonetheless, the device in question is a mod box that wrests top-speed from the BMW control nannies, sending the M5 into the upper reaches beyond the factory-issued 155mph. It's not available in the US, but in Europe it can be had for $649 — mere cents in Red Rocker bux. [Update: Damn our eyesight. It's available in the US from Turner Motorsport in Massachusetts]
Can't Drive 155 in Your M5?[Bavarian Falcon]
Related:
Hartge Breaks the Gentlemen s 155mph Agreement [internal]