If its an 8P A3 then its always going to be a dual stage system in the car.
The 8K airbag will work but will need a few pins changed over.
The single stage wheel is only good for the really old cars or the new ones. the mk3 TT now has a single stage airbag as does the A1 and the A3.
Is there a way to put the new TT steering wheel on a 2010 A3 8P? My car came without the buttons so I don't care a bout the buttons working but my airbag on the TT is single stage and the one on my car is dual stage. Is there a way to wire the dual stage harness to take a single stage airbag on my car?