First step in the process, is clean the surface. I didn't get any pictures of the cleaning process, but its best to use a clean lint-free rag to clean the surface.
This is how they looked after cleaning. Same as before, nasty and sunfaded:
You can see the staining even better here. Notice the runs in the color. I hunted around for an appropriate elevated device, and this old oil box seemed to work well:
Next, each panel will need a coat of Clear Polypropylene primer. When I sprayed the panels, the staining and fading seemed to almost go away, as if they knew of the impending DOOM!
I only applied one layer of primer. Since the paint is formulated to stick directly to plastic, i didn't feel the need to over do it. I also wanted to maintain the texture of the panels, and multiple coats or primer will distort the texture. Finally, i applied two coats of paint. Both light coats, but enough to cover the panel. Again, looking to maintain panel texture here.
After the two coats, i grabbed the storage door to compare how close the colors were. Pretty close, but not quite close enough for me.
I went ahead and painted the storage doors, and while I was at it the Top trim. This way everything matched. And once installed, here is how everything looks!
Excellent color match that should last a long time, and for a decent price to. All said and done, I paid less than $50 for materials and it looks brand new.