These white ABS fairing plates held the Zzipper fairing on my Tour Easy ‘bent since 2011:
Over the course of those six years I’ve ridden about 6 × 2500 = 15000 miles, maybe more, maybe less. I can ride at 15 mph for a while, but 12 mph seems a more reasonable overall estimate, making for a bit over 1000 hours. Figure the bike spends that much time sitting outdoors at the far end of the ride and you’re looking at what 2000+ hours of sunlight does to ABS.
In addition to discoloration, the plates have become brittle, as shown in the chips in third one down, and permanently deformed due to the pressure of the nylon bolts compressing the black foam against the fairing.
A closer look at the top plate:
My 3D print quality has improved a lot since then.
New plates of a different design are, as NASA puts it, “in work”.
The pix come from the new LiDE 120 scanner. It does a good job with the color, but has (for good reason) an essentially zero depth of field: if it’s not on the glass, it’s out of focus.
The Smell of Molten Projects in the Morning 
It would be nice to find a colorfast, UV resistant filament. There are a lot of products advertised with these qualities, but I haven’t seen anything which weathers well.
The best designed parts are no match for the first joule of sunlight.
As nearly as I can tell, you can get a filament optimized for any single parameter, at the cost of trading off everything else.
Given our conflicting requirements, it’s a wonder 3D printing works at all!
If UV is your only problem a coat or two of appropriate paint will solve it. As for brittleness that might not be caused by UV at all. I (and others) have had PLA go brittle with age and although ABS is a different animal it could still react the same or get brittle with temperature cycling or who knows what else
I may slather on some XTC-3D (which doesn’t claim any UV stability at all), cover with outdoor paint, then use ’em for a few years. Worst case: the epoxy peels off and I print another set.
If the junk in the oceans gives any clue, PETG should survive the heat death of the universe.