I had a few firearms Cerakoted. I have considered it on car parts, but typically it has a satin or flat sheen to it. There are a few Cerakote options that can be polished to a nice finish but it is a lot of work.
On the surface, the stuff is pretty much impervious to any damage except for what would remove the substrate (meaning, if it would gouge the underlying material, the coating isn't going to survive anyways). If I was doing a 4x4 or Baja/trophy build, I'd be coating everything in Steel-IT and Cerakote for sure.