Solution for damage from flat tires - thoughts?

My class C has metal liners above the rear wheels (well, mostly covering the space above them). I'm not sure they'd do much in case of a blowout at speed, but undoubtedly the do provide some protection against rocks thrown up by the tires and similar lesser hazards.

In short: it's a fine idea, and at least sometimes done by some makers, but not a panacea.