Getting faded plastic bits back to black

[Effortless]

Hi all,

after some advice please.

Some of the black plastic bits on my car are faded quite badly, see here...



I've tried the usual stuff from Halfords and Asda in the past, but all of these just seem to give the parts a wet look, which doesn't last.

Are there any dye-like products that will permanently get the black bits back to black?

Cheers,
Effortless.