I'd also recommend a filler primer too for any trim areas that have a textured effect, that way you can have it looking like a panel rather than just a painted dash :P

Could also just sand the textured plastic with fine sandpaper and polish it up with wire wool then brasso and a cloth to smooth it properly :)

What did you do dan? I'm thinking that I could get away with just smoothing the door bump strips and boot handle with sandpaper, but may need to use the filler primer on bigger areas such as the bumpers?

Also what about the door handles? What method should be used on them to give the best results?

My mate actually sprayed mine he's a spray painter lol. I just did my interior myself. The likes of the door handles and wing mirrors should be ok just to paint. Its only realy the front bumper etc. My mate just sprayed my bumper with the body kit covering most of it anyway. You can just about see its textured if you look closely. Id personally sand it and and then use wire wool on it then brasso to finish it off if you're wanting to make a proprr job of it. Either way its gona take abit of work. Eithrr that or change the bumper for a fully coloured one thats meant to be painted :)