Go back to the dealer and let them look under there. It may be starting to rust out. You might need something stronger than a cream, like naval jelly or muriatic acid. In either case, don't apply it without full-protection goggles & gloves.
Oops, I thought you said Volvo.
Well in this case then, just try not to scratch it when the TV cameras are on you, like all those baseball players.
