Could you not get the dealer to do an after-sales swap for them so to speak, so you still have genuine Audi ones? I know one has been done where I work on an A3 for a customer.
The UK Dealer will swap them for 5 spoke 18's from an a3 S-Line, but then it will just look like an S line. They say they can't get RS4 style 18's in the UK as no cars come with them as standard. They are a 700 Euro option in Germany on the S3 but Audi wont bring the option to UK. I can buy a set as a special order accessory for about £2200 from Audi, or aftermarket from a UK wheel distributor for £625 with Toyo Proxy T1R's. Its an angry sticking point as I didn't expect to pay this much for a car and be expected to change the wheels myself as Audi won't 'help out'.