Looks like current discount on an S3 is running at about £4900 including the £3k deposit contribution on drivethedeal. If I was ordering from scratch, I would order from there - always cheaper than Carwow, and probably cheaper than coast2coast cars (who were always best for BMW deals).
My salesmanat pickup said Audi are moving to the direct ordering approach soon. Your local dealership will be servicing, window shopping and collection only. No haggling, no deals, just what tge website says you'll pay.