Basically what is does is when you come to a stop at, say, a traffic light, the car turns itself off. When you press the clutch (or I guess the gas pedal on DCT), the car automatically turns itself back on so you can keep driving. It's supposedly a way to be economical and save gas. Hope that helps!
2015 AB/SO F80 M3 6MT | 19" Black M437 | AutoTechnik Black Front Grills | BMW Performance Side Grills | Painted Front Bumper Reflectors | Gloss Black Exhaust Tips
GONE 2011 SG/Blk E92 M3 CS 6MT