I’ve looked at the 15 ally/steely question. Scoot is right (achim agrees)... no such beast that takes the (very pricey 600/123limo) hubcaps.
There was an SLK wheel that a hubcap would fit, but not brilliantly, and given the price of the caps/ risk, I’d not want one flying off the wheel at speed. The wheels would need rear spacers too to clear the exhaust run