Note: There are variations of that plug model number with e.g. '-11' or other suffixes. They are not interchangeable. For the A3, you need the BKR7EIX exactly (they are correctly pre-gapped to 0.030").
A coil failed right at my 25K service, so as soon as I got the car back from the dealer I replaced the plugs. Since the coils are removed to reach the plugs, these instructions also cover coil replacement.