Help fill holes in Trunk lid

Fiberglass cloth and resin is not a cure all either. Different expansion rates than metal and usually doesn't take long to crack. Resin has zero strength by itself and the only thing that holds the patch on is the thin boundary layer that forms between the metal and first layer of glass. Like bonding a glass scoop to steel hood it only lasts a short time. I would use long strand reinforced filler before I used cloth and resin if I just had to cave and pave.