I've got a 3-0 TDi Auto - and it's got Adaptive cruise control. When I come up behind another car and the Adaptive cruise control decides I need to slow down, what are it's options? Obviously to reduce the gas but I also sense sometimes it brakes automatically - am I imagining this - is it just engine braking? Would certainly recommend the Adaptive cruise control but the Audi Lane Assist is a bit of a waste as I can't believe the meek vibrations it sets up to warn you that you're changing lane would actually wake you up if you were beginning to fall asleep.