I am going to have a vagcom test done on the car this week. I have been having this lumpy acceleration and cruising speed problem when driving, it happens in tiptronic mode too. Someone said to me it could need a gearbox oil and filter change and that could solve the problem. I'm hoping i don't need the rather expensive gearbox sensor part which i think is around £800. Any advice is truly appreciated plus if anyone knows where is best to buy the gearbox sensor ? Many thanks to all.