Car drives perfectly and changes gear from 1-7 with no issues. When accelerating gently the car drops from 7th to fifth. If you release the accelerator the car should change up 5-6-7 again but stays in fifth like its forgotten it has more gears. If you put it in manual and back to Drive it changes gear fine. It also changes fine when in manual. There is never any hesitstion and there are no fault codes stored. The transmission fluid is due for a change in 10k miles. It has been in an Audi garage for almost two weeks. They have said it was speed sensors which it wasn't and said because one of the back tyres was much more worn than the other that could be affecting it. They changed the tyre and it didn't fix it. They're now saying the other back tyre which is barely warn could need changing. The car isn't a quattro and both front tyres are new. They also insinuated it needing a service could affect their readings so I agreed to have them service it whicb cost several hundred more than using my local garage and genuine Audi parts. They also changed the front disks and pads as they might affect the outcome of the tests. They were an advisory for MOT a week previously. The MOT tester said they would need doing in a few months. The car is under warranty for four more months. Their service in regards to providing me with a car has been superb but I have not been happy have to pay them to do the service, brakes and tyre which cost substantially more than using my local garage with genuine parts. Does anyone have any idea what might be wrong with the gearbox please, they even said tonight swapping the wheels around might have fixed the problem but haven't had chance to road test it yet (tomorrow). Surely swapping wheels would just move the problem around with the same outcome!? Please help.