Can I use enamel spray paint on plastic?

I want to paint a pair of black out door speakers white. I found some enamel spray paint in the garage. Will it work?Can I use enamel spray paint on plastic?
There is a paint called plasticoat made for plastics. If you sand the plastic first it may stick, as long as the spray paint you are applying is not real glossy. The factory uses a system called burnishing. You heat the surface with a propane torch being very careful not to bubble the plastic. This process is also used on plastic gun stocks. Sanding and just spraying would be the easiest most simple way...Good luck