I've tried the painting route with "mixed" results. In a lot of cases, the plastic isn't just dirty, it is literally wearing thin (such as the power window switches). For the power lock switches you can get a set of stickers from Rodney. However, since the switches aren't that expensive and still available it might be worth your time to just buy new ones.
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-Chris
'85 V6 SE 4sp (SOLD)
'88 GT Auto (fun car)
'03 Sentra SE-R Spec V (Daily driver)
[This message has been edited by Chris_narf (edited 03-20-2009).]