I repainted mine a year ago using professional bodyshop paints which are readily available to DIY'ers.
Sanded it down to bare plastic to remove previous bad paint jobs.
Primed with plastic primer (this is key if you want your new paint to stay on. Its readily available in aerosol)
Primed with 2k high build primer to repair stone chips, minor marks (you can skip this if your spoiler is in good nick)
Sprayed base coat 2k black
Lacquered with 2k 'Matt' lacquer.
Looks very original and 'as new'
Will never fade again.
I do like the idea of the colour not fading! I was dubious as to the quality of finish - whether it would look really naff and an obvious paint-over job - but from what you say, that is not the case? I don't suppose you have any photos you could post?
One point which worries me, though......I thought 2k primer and lacquer both required a hardener - which contained isocyanate and therefore could only be done in a spray booth with full respiratory kit
Could you possibly elaborate on the brand/manufacturer of the paints etc required? I don't fancy getting the wrong stuff and frazzling my lungs
Thanks for your help - much appreciated