I thought I would jump in on this post.... its a long story of general incompetence of East Kent Audi and the seemingly non existent mechanical abilities, but I find myself needing a new rear diff as mine has developed a rather annoying whine at 70 to 80 mph.
I've just had the transferbox replaced also due to the same garage making things fail.
So my rear diff has part no 0BR525010B which according to 7ZAP fits A3/S3, TT, Golfs, yetis, superb.
I've found one that looks identical 0BR525010E from a Skoda Yeti 1.8TSI. Its a great price and only done 4000 miles. But that part number on 7ZAP only lists the Yeti.
Does anyone know if it would fit and work correctly? (same ratios)
Maybe I would need to transfer my haldex onto the diff.....
any help or advice would be greatly received.