With reference to the trukote sales pitch in Fargo...what is the black stuff covering the bottom of the car? I have one or two spots where it got scraped off, so want to touch up. I noticed that while on the outside it is hard(ish), b but near the exhaust, after some driving, the stuff was pretty soft when warm.

Also, the very bottoms of my fenders, aft of the dirt flaps, have some rust I want to clean up. I am thinking using marine grade primer and paint, just to cover that area after sanding it, in black.

And finally, after a reinstall of the original windshield, i have gaps between the rubber trim and the body at the bottom corners of the windshield. Solid paint there, no bubbles, nothing. Should I fill in these gaps with something? Can I fill it with black silicone?

Thanks!