Lol ffs rich....why can't we all have jobs like that haha!!! As you know i like to bufty from time to time, i normally polish the backbox that you can see and the first few inches inside lol, i just use meguires metal polish or autoglym stuff. Once it's clean it's easy to do when you wash the car....i've always been that sad though so haven't ever had it build up too much but wheelcleaner is a good first step or as said somethin more abrasive with the likes of a brillo pad etc.