Chemical to darken black plastic?

[NitrousO]

I heard there was some chemical I could use to darken the plastic parts on the bumpers and on the door handles. Anyone know what its called and where I can find it?

[Alexlind123]

"Black Again" Google it. It works well.

[epj3]

Try mothers back to black, I also find that turtle wax ICE does one thing very well - turning trim back to black.