I can't remove the caps and neither can the dealer. Now I can no longer fill the tires with air. Apparently mixed metals (aluminum caps and steel valves) can bond together. I tried WD-40, heat and pliers but couldn't get the damn thing off. My arms are throbbing and I'm getting blisters from using all my strength. The only option left is to damage the stem valve sensors, which cost $330 to repair. Should have stuck to the plastic. Big mistake buying them.