If it's metal it look powdercoat...if it's plastic, need to be thick!Interesting question. It's got to be something strong enough to hold the weight of a person and protect from road debris that will strike the bottom. I would think it would have to be metal, but plastics these days are pretty amazing. Hmmmmm?
Anyway i'm gonna put Gravel Guard on it...the same product they put in the cab of pick up truck! Is very resistant and look better than a flat plastic panel! Here is the result with the T-Rex!Definitely plastic in the cab, but I'll bet there is something more underneath.