Originally Posted by shiv@vishnu
You find me a good switch that will fit somewhere nicely on the 335i dash and I'll do it
Seriously,why not the actual //M button from the E60 M5? It might not be the cheapest solution but it would definitely look "OEM"
(*edit* didn't realize the M button is actually on the steering wheel on the M5...might not look at home on the dash...but the "Power" button might!)