Nearly all bodyshops will be able to give you a quote and do the work, best to go with someone you know or know of or have seen their work
it all depends what exactly you want doing
i was lucky with mine as my unit is surrounded by bodyshops so it was done favour for a favour but i know it was a lot of work but that was due to the amount of "flatting" required because of the flakes in my paint.
as long as they know what they are doing painting plastics you shouldn't have a problem especially seeing the amount of plastics painted on modern cars
get yourself a spare set of plastics to paint if you go ahead that way you can always return to standard if you're not happy or decide to sell

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or olives???
quote motonacio "this is to certify Meach is not the prat you'd think from his posts"
http://www.youtube.com/imeach