Put it towards brakes. There's probably no better use of your money at this point. Read up on the 345mm mk5 R32, mk6 R and 8P S3 brakes; and the later generation 340mm 8V S3, mk7 R, mk7 PP and mk7 Clubsport setup. You can combine parts of both setups. Probably the most effective £300-500 brake upgrade available.
Sit on your money and read up.