Black Audi grill badge
Silvertec indicator bulbs to get rid of fried egg look
Facelift rear light cluster
Wind deflectors (some people like these, I don't personally but they are cheap)
Audi OEM logo'd tyre valve caps
LED number plate bulbs
S-Line logo custom mats from Autostyle
If you go to Autobulb Direct website and input your reg number it comes up with the bulbs you need. I put in the reg for my 07 and 61 plate S3 and all the indicator bulbs (front and rear) came back the same.
Cheap option: 581 PY21W Silver Indicator bulbs
If you want something a bit more upmarket these are listed: 581 Philips Silver Vision Indicator Bulbs