I've had great luck with Krylon Fusion rattle can paint for under hood work I've done. I've done the engine cover, the fan shroud and, before I put my CAI on, the air intake box top and duct. No problem with heat bubbling the paint, etc. I could smell the paint "baking" the first time I drove it after painting but no damage and the slight smell went away in a day or so. I didn't sand at all but I did do a good toluene wipe down before starting. Now, saying all of that I have not gone back with a clear coat (I don't know if Krylon makes a clear coat in Fusion) so I can't offer any suggestions other than it would make for a smoother, more finished look. Mine is a very basic Mopar blue and white scheme but if you dig around the Z some there are some really nice homemade paint jobs to check out.
Good luck and let us see the finished results.
Marching to Mamasita's beat for a real real long time...