Most all polishes contain waxes of some sort. If not to help the shine, it's a carrier for the abrasives.
Get some lacquer thinner or metal prep (I prefer lacquer thinner in most cases, but don't wipe painted surfaces with it!) and wipe the part down prior to paint. Agitate with a brush or cloth that has some "fluff" to it so that it can really scrub any contaminants off. Once the surface is truly clean oil free, prime and then paint. Always start each layer, including primer, with a dusty "tack" coat to prevent runs, wet spots (which will dry funny or not at all, or won't adhere), and bring out anything that wants to "fisheye" before you get too far into it.
