I've got an 8L pre facelift S3, but my headlights have become a bit minging, and I've seen people use a fine grit sandpaper to return them to their former glory. The question is.. What do I use? Am I going to need to order multiple types? I seem to remember them being plastic rather than glass.. Is that the case for all pre facelift models? Do I apply the hard work by hand or is it going to take forever?