I've got a gearbox bearing gone in mine, i'm still running it though but Audi won't replace it under warranty as my car was lowered and with non standard wheels!
Tbh though I just fkin laughed at the service guy who tried to tell me some old crap about the driveshafts going in at an angle causing wear on the casing. They promptly charged me for an hours labour TO REMOVE THE GEARBOX and investigate the fault. Yes you heard me right, remove, diagnose and put back on a gearbox in 1 hour!!
Anyway, i'm going to write a letter to Audi HQ asking for my hours labour charge back as I put the car up on the ramp at work and there is not a single spanner/ratchet mark on any gearbox bolt. I will also speak to them about the gearbox bearing as it's cleary not linked to the lowering at all as the bearing that has gone is at the rear of the gearbox.
If I was you i'd be on the phone to your local dealer if they are less than helpfull contact Audi HQ direct, i think they are in Milton Keynes.