Might be over kill though. You can get primers made for plastics, then gold spray paint. Just examples...
Primer: http://www.rustoleum.com/cbgproduct.asp?pid=119
Gold spray paint: http://www.rustoleum.com/CBGProduct.asp?pid=114
You might want a clear coat on top of the gold to protect it. Rustoleum claims that gold paint finishes really tough, and "Do not use with clear coating to avoid dulling the finish." But you'd have to make a judgement call with that one.
But other than that, as long as it's done correctly, it should be good to go.




