Dock

I think more so when the body color isn't dark. There is obviously a better visual blend paint-to-plastic on a black car, although the gloss (paint) to non-gloss (plastic) is still somewhat of an issue even then.

When I considered painting my Turbo's lower parts, my paint guy told me that if the plastic parts had been treated with any detail products to make them look better, he may not be able to paint them (that is, he might not be able to remove enough of the product to get an acceptable surface to apply paint to).

GreggT

Good point Dock.

Also......the composition of these ground effects parts is relevent.....if memory serves Porsche uses, or at least did use, polypropylene rather than polyurathane.

Kevinmacd

There is a paint product out that allows paint to adhere to plastic, regardless of the base type. Clean off all silicones apply the adhesive coat, then paint as normal.

"Dupli-Color® - Professional Adhesion Promoter:
Dupli-Color® Professional Adhesion Promoter increases adhesion of all paints to polypropylene, polyethylene, TPO, ABS and related plastics.
Provides improved adhesion for paints
Ideal for use on primed metal and automotive plastics
Please click the item below to purchase.
DUP DPS105 - Adhesion Promoter"

SSST

It works great. I used it as the base coat to paint the mud flaps on my truck. Three years, 43k miles, and some pretty hard duty on and off road, and there aren't really even any chips in the paint on the tire side. The "clean sides look like they did the day I painted them.

It's really good stuff.

Dock

That can be the pivotal issue. The plastics seems to be somewhat porous, and completely cleaning all silicones that may have been applied can be difficult to impossible. This is obviously not an issue if no silicones have ever been applied.

Kevinmacd

Use a laquer thinner a couple of times, be careful against any painted surfaces to clean,it will take off paint. If you are careful the silcones will not be present.

Kevinmacd

SSST that what I did also on my truck mud flaps, needed them to match my two tone, rather than black. Yup still adhering and gong strong.

Tim Wasmer

All are great suggestions. Yes, you must get all silicone crap off. I used a degreaser and wheel acid. And scrubbed with a scotch bright pad. Applied a few coats of sand-able primer. Then paint from a company on eBay that does color match paint. Then a few clear coats and you are done.

I put clear bra on the impact spots for good measure.

bux996tt

I like the lowers painted. Looks a bit different and clean. Your car looks great.