On my C5 RS6 the gearbox often goes into failsafe mode when the car is cold and been sitting unused for a few days.At the moment temperatures are hovering around the freezing mark.When you turn the car off again and restart it it is fine.The initial "clunk" which you often get in auto cars when gearboxes are cold seems to set it off to go into failsafe.Is this normal,and should you let the car warm up for a few minutes when driving off,and shifting into gear? Also I was going to get the oil changed in the gearbox,but my local Audi dealer says the gearbox on these cars are sealed and not serviceable.This made me think if this is true as my 1998 S8 which I think has an identical gearbox had its fluid changed 5000 miles ago.