G8tor

New to me 2015 GTS lease trade in. Since it was a lease I don't think it saw the best of care, but it's washed up pretty nice except for the centerlocks.

One of them (left rear) looks fine, the other three look more grayish than black from what appears to be almost like a calcium (white) deposit, plus one has what looks to be rust in the teeth.

Scrubbed with a soft brush with car shampoo and in a few small areas tried a few things on a Qtip (alcohol, degreaser, lime away) but to no avail. Any ideas on how I might clean these up?