Strange performance

[Doid]

Hi Everyone. I sold my 2000 D2 4.2 petrol 70K in the summer when I bought a 2010 D3 4.2 petrol. It has a strange performance quirk which perhaps someone could explain please.

If I accelerate from rest gently, such as when sequencing into a roundabout, there seems to be a hesitation which I correct with a slight increase on the accelerator pedal. The gears will have moved from 1 to 2 (maybe 3). There is then a sharp, sudden acceleration which has caught me (and my passengers) unaware a few times.

Harrogate Audi and now Leeds Audi have found no fault even though I have demonstrated the problem. It only occurs under gentle acceleration.

Does anyone have any ideas please?