I have a green abs canoe that I bought from Academy a couple years back. I keep it stored outside in the sun, bottom-side up. So far I can't see any sun damage; but should I treat it with Armor-all or a similar product to prevent damage?
I'd appreciate some advice from anyone who has knowledge or experience. Thanks!

It will fade eventually and it's not going to be good for it storing it in direct sunlight year after year.

Eventually everything will break down especially plastic, due to exposure to the direct sunlight. I would at least spray it down with a plastic protectant, and then cover it with a tarp.

303 marine protectant and cover it with a tarp. Leave some air between the tarp and the canoe surface. Also store the canoe upside down on some kind of racks or sawhorses as opposed to directly on the ground. The racks should go under the seats.

http://www.sdplastics.com/ultravioletresistance.html

This site lists different "plastics" resistance to UV.

It is possible that there is a protective cover molded on some applications.

Thanks gentlemen for your advice. I'm now considering building an awning on the back of the garage for the canoe and other at-risk toys.
Roadtrip, it's on sawhorses, but I wouldn't have thought about putting them directly under the seats. Thanks.

+1 on the tarp. If you can store it in the shade & off the ground too. when it comes time to sell it, you'll b glad u did.