I have figured out launch control on the MK6 GTI. The owners manual says to turn off ASR, floor it and let go of the brake. That results in acceleration but a lot of wheel spin. I have been experimenting and I have figured it out. Turn off ASR, hold the brake, bring revs to 2-2,500rpm. Let go of the brake, and as the car begins to move gradually floor the throttle. This will result in a rather perfect launch with little to no wheel spin. There is no jolt or thunks from the transmission or anything.