I've used the Duplicolor Anodize-it paint. You buy the base, spray that on, then spray color over it. I actually like the look of the base alone, though its not chrome. I had a difficult time applying the color evenly over it. Then I clear coated, spilled some gas on it, and it all came off. Rather disappointed.
I've used the spray on chrome a number of times too, and it is basically silver paint. Perhaps if you could sand it really smooth it might look like chrome. The stuff wears very easily on plastic, wood, and metal, so be prepared to clear over it.
If I were looking for a cool chrome like finish, I'd try the following (cut out to the shape of the guitar):
1) mirrored acrylic. It's clear acrylic with a mirror layer on one side. I've used this for pickguards, and it works well. Fairly easy to work with, all you need is a jigsaw and a dremel and some sand paper. It does scratch though, probably slightly more than the stock finish on a guitar.
2) Polished metal. I've been playing with this and haven't gotten really great results yet. I've tried aluminum sheet mostly, sanding it, then using steel wool
, and then polishing compound to get it really shiny. Looks great. Unfortunately it will oxidize or tarnish, so it needs to be coated with *something* but I haven't found anything that doesn't make the metal look slightly hazy.