Found some texture paint on eBay. It's not cheap, but the results are REALLY good.
I bought this to use on parts for my Mk2 Jetta, and I've been playing with it over the weekend - crap pictures I know, but if you can imagine somewhere in between the two (flash and no-flash)... it looks like a proper factory finish! You prep your item with etch primer, then matt black it, then lightly spray this stuff on it. You only need a very light covering to get the right effect. Too much and it dries smooth. Touch dry in about 20 seconds... Awesome!
I think I'm going to do something custom with the Jetta grille this time. Going to try and not over do it with this stuff, but I can see myself getting a bit carried away with it!
Find it here: