Rude point of information here: Most plastic breaks down when exposed to sunlight and heat, rapidly. As a child, with the long hot summers here, I remember finding plastic milk jugs in the woods, exposed to sunlight that crumbled when I picked them up. I also found discarded beach balls, rubber rafts, plastic sheeting and plastic toys, which, if they were in places with little shade, broke easily apart. The rafts, sheets and balls crumbled into flakes.
Car dashboards used to split with age and fragment. I remember pounding on the padded dash of an old car of mine and discovering that the flexible plastic cracked in a round pattern where my fist hit. Even tail light plastic, after some years, became fragile and broke easily.
When they came out with PVC pipe, I wondered about it but everyone assured me that it was as good as iron or copper but years later, finding left over pieces that had been laying in the weeds for a few months or year, I found that the stuff shattered easily! Using it for plumbing away from the light of the sun allows it to last for ages, but expose it to sunlight and it deteriorates quickly.
Brightly colored kids toys, like those riding cars and carts, if left outside all of the time, eventually cracked and broke but those new slides and things are made of a different plastic that never seems to grow brittle.
Some people I know take their car seats out of their cars daily or park their cars in a garage, but I guess leaving them in the sun all day would cause the plastic to break down with time.
Isn’t it so nice that the makers tell you that? Whatever happened to truth in advertising? I suggest you use armor all on all plastic surfaces exposed to the sun and use it frequently because it seems to work well in delaying the effects of the ultraviolet light.
A little observation: Glasses coated with scratch proofing and UV protection, which costs more, do not retain these properties over 4 to 5 years. As you clean your glasses, you rub the stuff off. They don’t tell you that either.