When i went to get new tyres, i parked it in the garage and noticed with the change in light that just the top face of the rear spoiler had faded quite badly. I've clean and polished the car a few times since which improves it at the time of cleaning but hasnt improved things permantly. I even tried some of the coloured polish/waxes but not sure if it was really the right stuff.

Have you tried sealing the surface in after polishing with a sleant and/or wax? Which polish are you using by the way?

Detailing World is a good place to look for advice as well.

my tip is to keep your pants in the draw out if the sun:D