Thinkin' show polish might not be the best long term solution. I use vinyl dye, satin black, spray on a rag and wipe light coats to build to the color you want. for a couple really bad ones needing a lot of fibergalss reapire, just spray. The satin is a bit too dark, but the best I could find to get "close" as the originals have a grey-ish cast and not quite full black.