Hi, just got this otherwise superb 230 clk, but like a lot of these one of the wheelarches has just started to show signs of rust. Not as bad as some I have seen but needs to be seen to before it spreads. I will have to initially pressure wash the dirt off first but then what?. which is the best way to protect them, would Waxoil do? or do I need a zinc primer first? A bodyshop would probably do the rest as I have no chance of matching the colour. Any ideas?