[Markr]

Yes, probably a good idea.

When I had my 1st A8L i had a droning noise that came in a 65mph, which Audi could find no issue with and fixed under warranty with a new set of wheels and tyres - all this did was move the problem to 80mph or thereabouts, and eventually came back as the tyres wore.

2nd attempt included test gear from Germany, and other techs from Milton Keynes, no fault found, and then they got mine and a new one on the ramp side by side and did a full compare, and only thing found was a slight difference in the play in the propshaft, but not enough to cause an issue, however in desperation they authorised a new proopshaft, and problem solved.

Morale of story here is that it may look ok, but may not be, so needs a bit of lateral thinking when comparing against a known good one.

Good luck.