I did mine with semi-gloss engine enamel, half-ass job, did not remove them, just masked the hell out of everything... Looks good, but I am going to re-do them with that new Krylon Fusion (plastic paint, I don't think heat is an issue here, but please correct me if I am wrong).. this time I'm taking them out and painting both sides too. Prob will need a wire brush (manually) to get the underside clean and smooth.

It does make a drastic improvement, well worth the limited amount of work

 

im not to worried bout heat.but what about if i spill coolant(from overflow jar on side).does the fusion paint come in semi gloss?i wouldnt use a wire brush i would think it would scratch plastic.im gonna pull mine off as well.but am thinking of useing some cleaner/stripper.i want to paint my radiator shroud as well.thought of fussion but would like to know if it the most durable paint to use?i would like something that is solvent resistent.

 

yeah, maybe a vinyl brush or a pressure washer would be better to get the bottom side clean Not too sure about the chemical resistance properties of Fusion, but I'll look into it...
I'm not advertising for this particular company, but they show the range of colors
fusion

 

Fender paint

Spilling coolant will not likely be a problem for your paint. Glycol is generally benign unless you drink a couple of pints of it. The threat would be hydraulic fluid, but that is easy to manage.

As a general rule, you want to consider a Gloss finish since it has fewer pores and is inherently easier to clean and more durable than Semi, or especially Flat. I guess you could clearcoat Flat, but that would defeat the purpose.

If you need to sand it, you'll want to take it down to 400 grit or more, otherwise the rough surface will show right through the paint.

Take care.

 

I just painted my entire engine bay including the fender wells and fan shroud, with that krylon black paint, IT LOOKS AWESOME.... U might need to do a little light sanding b4 and after to get the fender well perfect.