Montana SV6 problems

[kody]

My folks bought a 2006 Montana SV6 last year from a dealership but recently we noticed the valve stems are chaffing against the hubcaps. Since nothing is out of place and it was the same on all four tires I'm guessing its a design problem, also a safety concern if one of those valve stems were to become chaffed all the way through...they were cut pretty deep. We went to the dealership on another issue and mentioned this but he was no help and my father had to pay to have all his valve stems replaced. Now they are started to do it again!!

Has anyone ever heard of this happening before?
Is there a solution for this problem?
What about replacing the rubber valve stems with metal ones?

Thanks