Our old mopars have sheet metal a bit more resistant to flexing than a Probe

In my limited experience, the final result has been on the soft side, so I don't think flex would be a problem.

More generally though, I'm signed off from the idea of using this on my dart at this point. I found some of the original enamel behind the rear bumper, and polished and waxed it, and when I looked into it head on, I could see a reflection (not mirrorlike, but a reflection). When I look head on into the test piece I've done with Rustoleum and Rustoleum pro,(under the same light conditions), after waxing I can barely see anything. It still looks nice from the side, but that's only part of what I'm looking for. This, plus the fact that I can put scratches in it with my fingernail, has pushed me over the edge. I need more of a shine. Miracle auto body, here I come. Best wishes to other rollers; I think I'll use the Rustoleum spray for touchups and door jambs though, but for my body I'm hanging up my roller.