So ive finally got myself an audi a6 avant s line 3.0 tdi, in aero blue. 05 plate with 55k on the clock. Picked it up yesterday and left edinburgh for Buxton this morning. gearbox is acting strange, it doesn't always do it so not sure its mechanical? when I'm cruising in 6th gear and accelerate the gearbox drops to 5th with a big clunk. It doesn't always do it but when it does its bad. Same downshifting with the paddle. Sometimes its smooth as silk sometimes it clunks. And similar when slowing down coming down through the gears it clunks and lurches when going to park. please someone tell me its as simple as software also so noticed when on cruise control it sometimes wouldnt maintain speed, speeding up and slowing down. Hopefully related to the other issue. The car is under extended warranty but only to the cost of £2k can someone shed some light?