I think this is so subjective, a simple change of tires can have a massive effect....
I always remember my S4 turned even more vague when for some reason I decided to get some Hancook tires, binned them almost straight away and stuck with the bridgestone's.
Do all S3's come from the factory with the same tires? as I dont have any of this vauge steering on my 09 car....
I think my car has Dunlop tires....