I'm amazed at how you guys can afford to run an S3 at such a young age!
I didn't even buy a car until I was 20. OK, I had my mum's Polo to drive when I was back from Uni during the holidays, but whilst I was in Nottingham I had a bike or used the bus.
I bought a 1.0 Polo for 2.5 years until I started my first job in the autumn of 1996. I started on £16k a year and once I'd paid rent, I could just afford to buy & insure a 3 year old group 10 Ibiza GTi (couldn't afford a Golf GTi).
House purchase in 1999, kit car purchase in 2001 and S3 purchase in 2004 - aged 30. I still think the S3 is quite an expensive car to run and I'm earning a pretty good salary. Good luck to you guys, but just remember, it's all good borrowing money, but you have to pay it back eventually!