call them and ask. It wont hurt.
I viewed so Chrysler Voyagers a few weeks back and passed comment to the salesman that everyone one had corroded alloys.
He said that nearly all new(ish) cars had same problems but that most companies would replace under warranty, so any car i purchased would have a new set of alloys if i requested under warranty.
He also said that the companies arent changing the wheels on the cars when made because it doesnt happen to any of the wheels in europe, only in the UK. Maybe something in the salt grit used this winter