I had my rear diff replaced due to scoring on the gear. It was easy at the dealer and difficult with Ineos in UK. They required multiple tests, video, and stalled until the 30th day in the shop and finally approved when Ineos USA said they would be buying the car if they didn't fix it as it was a clear warranty issue. I've got 10k on the new rear and will take it in for the 12k change. I did my own changes at 3k and 12k and Ineos tried to call that into question. I had photos and receipts so that was easy to refute.
Rear Diff Replacement
Rear Diff Replacement
