Having sold my R32 last week, I went and bought an 01 Nogaro Blue S3 as a cheap(ish) runaround until I get an M3 or S4 in the new year. The first thing that struck me was just how **** the standard lights are on the S3. The cut off - which is usually sharp and defined on xenons - was fuzzy and vague. They look yellow and are aimed really low. My R32's were much, much better. Also, I never understood why Audi moved the dipped beam (projector) closer to the centre grille and on the inside of the main beam. Not only does it look crap it must surely affect beam pattern?
I changed the standard bulbs (Philips D2S bulbs) to unbranded 5000k jobbies, and aimed the lights a little higher which has improved things somewhat, but the problem is bad headlight design by Valeo/Audi as the light output/cut off is still not comparable to most xenon equipped cars. When you look at the Renault Clio Sports, Mercedes E Class and most BMW's you will see a world of difference.
6000k may seem to make the headlights brighter, but in actual fact you will be losing useable light from the 4300k bulbs. 5000k colour temperature is closer to natural daylight and you will lose no noticeable light output, so I'd recommend going for these.
Visually, I don't think there's a lot you can do to make them look more polished and modern, the projector lens seems to be quite restrictive in that way, but my 5000k's look far better than the tired 7 year old OEM bulbs they replaced and they even flicker very slightly over bumps giving them the purple hue which I think you're after. Give it a try, the bulbs only cost me £30 from eBay, but don't get anything higher than 6000k, leave them for the cabbies and Jap scene.
Edited to add: this post is long and rambling.
Summary: Buy 5000k D2S bulbs and aim lights slightly higher.
