OK the car is at the dealership and I managed to demonstrate the noise to a technician, however he did suggest it might be normal, not convinced by that. I suggested they put the car up on ramp so they can start the engine with someone underneath, if it makes the noise I am hearing, and they actually do hear it, then they should have something to work on.
The loaner turned out to be an A3 but it is all my nightmare's rolled into one; it's brown, it's a three door, it's a 1.6 diesel, it has s-tronic and, worst of all, it has this archaic system of using a key to start the engine, jeez...
Anyway, my initial impressions were, deep breath, of the diesel mated to the s-tronic were mixed, some was good, some not so good. It still seems that they haven't improved auto mode much over the cars I was was driving in the '80's. More throttle has to be applied to pull away than anything I am used to with my car and the kickdown still seems to be lethargic. However I've yet to try it out with the paddles so I expect an improvement. Oh and it creeps forward too much when no throttle is applied, something I guess I notice more after having driven manual boxes for so long. I could write more about the car, again it's mixed, but to cut a long story short it isn't anything like as refined as my 1.4 engine.