Diamond Cut

Is what this wheel treatment is called, I understand.  It looks pretty good on the car (here is a BMW page), but the surface is vulnerable, after a while, to corrosion.  This is normally started by other damage, I'm told, but it's really annoying when a pristine wheel starts to suffer from the spread of mould-like corrosion.

This car's wheels, only 8 weeks old, are still in good shape, but who knows when a nasty and aggressive kerb will strike . . .