Mine has a drain that Audi can't find. Despite 2 x 2 week periods in the dealer. No BSG failure (yet)
To add to the above, Audi would now need me to authorise £1000 of Labour (based on hours needed) to strip the rear of the car and examine everything else to find the drain / spike.
Because
1) The Audi Approved Used Extended Warranty does not cover wiring (full stop) if it is a wiring issue.
2) Despite all the time in the workshop and technical assistance, they cannot determine where the issue is. Gateway controller is mentioned but they don't know without testing every module.
So, it's catch 22. I'm taking it back and I have put Uber on my phone in case it dies on the road. Then the dealer would see what needs replacing. 35,000m with FASH.