I hit a piece of metal going around a curve in South Dakota. Nice welcome traveling into their state.
Tried a couple of foam types to repair. The one I settled on was the yellow in a red spray can sold at Home Depot, Lowes.
Used an old pair of gloves to move it around in cavity building the base and then adding some volume to existing. As the stuff expands while curing as I’am sure you know..
After an overnight cure I had to touch up a few spots so the coverage blended to existing thickness.
Used an old hunting knife for trimming excess where needed.
Flat Black spray paint for several coats seemed to be pretty much the color of choice.
After you drive in a rain storm the repair is no longer visible.