I had already replaced 2 coil packs due to misfire, this was approx 2 years ago, when i took mine to audi for them to check the coils they said all 4 were of the new part numbers (2 must have been done before i bought it). They happily gave me 2 new ones for the ones i had replaced, they could not offer a refund, but i now have 2 new spare coils, just in case!!