One comment that I will make here, I bought a used set of four Audi A4 B8 18" 5 spoke alloys for use in winter only, one was nasty so I bought a single brand new old stock one to replace it, then after removing the duff tyres handed them into my local powder coater. They came back look good but not perfect, not a problem as I was only using them in winter, handed them into Costco and got Michelin Alpin Pilots fitted, so far so good! Now three winters later I discovered that all four are leaking at the valve body/wheel contact point, so I needed to get all four valves replaced and wheels rebalanced! So, what I think happened here was, powder coating process puts a thicker coating on the wheel than factory paint and lacquer, so the valve hole would have ended up being too small for the valve, so Costco tyre fitters probably reamed these holes open again and so damaged the powder coating at that point on each wheel - and so the moisture has got under the coating and is cracking it, when the valve bodies get handled during normal pressure checking, powder coating material has moved and caused a leak. When I get my Audi S4 B8 19" 7 double spoke wheels refurbished (summer only use), I'll be getting them painted and lacquered to avoid that happening again.
I did also find out that when you get powder coated wheels back, you need to open back out the centre bore and the wheel centre trim hole or they will not fit.
