I would recommend starting by using a heat gun to heat the part thoroughly to a relatively high temperature. Not so hot that it melts, but pretty darn hot.  That will make the fading disappear and from there you can use an applied product to help even out any remaining differences in the different parts, but the differences will be much less radical. 

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Mark Belanger
Sent: Wednesday, August 29, 2018 5:22 PM. 
To: vanagon@GERRY.VANAGON.COM
Subject: Plastic Back to Black?

Greetings all,

I recently got a replacement center piece for the airdam on my '91 GL
Camper, which I lost on a bad trail. It's pretty faded, so I'm wondering
whether there is a reliable way to get it and possibly the lower grille
closer to the original black?

Typically I've seen recommendations of using matte black spray paint, but
I'm skeptical of paints ability to adhere to plastic when it will take such
abuse from rocks and other road debris.

Has anyone used Bondo Black or Meguiars Ultimate Black with any success?
I've also heard of some technique using a hot air gun, but haven't yet
researched that.

Thanks much,
MB
--
________________________________________________________________________
Mark Belanger - mbelanger@gmail.com