i'd have to say the Werkstatt Acrylic kit would be the best. mate put it on his Silver A4 Cab, it was just awesome.
review/write was done by Richard here: http://www.audi-sport.net/vb/showthread.php?t=73248
For tar spots I use Autosmart Tardis, it just melts the tar spots. A small soft brush will help remove any spots. As to Brake dust/dirt on alloys, I use Meguiars Wheel Brightener, once clean get some wax on the alloys to protect them.
lol not 30 quid for the one I have :) this is one of the best out there. most fleebay catch cans have nothing in side of them just an inlet and outlet. this will not allow Oil vapour to condense and then run to the bottom of the tank.
an Explanation of the one I am using is here...
persoanlly i use Meguiars Wheel brightener to clean them, Autosmart Tardis to remove tar spots. I then use any old polish to get them clean and prep'd and then use a few layers of Poorboys Wheel Sealant to protect them.
You can buy the Blackfire Wet Diamond All Finish Paint Protection seperately if you like. This goes on very easily with a pad applicator like the Lake Country CCS pads however obviously for the best results a full detail is required but once you have the basics done then I do it by hand every...
Richard has a good set of guides for all coloured cars. since yours is a drak Grey and you want one of the best then I would recommend Blackfire Wet Ice Over Fire Shine Kit it is very easy to use and gives stunning results.
Also have a look here for other recommended products. Recommended...
Rich when do you expect to get some more Pads in? notice your out of stock for most of them that are mentioned here.
also whats the best way of cleaning Blackfire Gloss Enhancing Polish off the pad? I noticed it is very hard to get it clean using most detergents.