Most of the wooden bars are broken by residents not paying attention. I broke one. So now instead of breaking a wooden bar, residents will have more damage to their cars. If they snap off a metal bar, it may cause greater damage, not only to his car, or injury to himself, but others as well. No one breaks a bar on purpose. I know I didn't.
Bad Idea. The mfg. put a wooden bar there for a reason.
Dick Cardoza