I don't understand why $150+ Oakley's need to be babied like this (at least according to some, I haven't had them long enough to know personally) but I've had $20-70 sunglasses last for 7-10+ years without ever not being stored in the car, from -20° to over 100°. I mean, they are sunglasses! Using them for driving must be one of their most common uses.
Thing is most of us wear vintage pairs that are harder/more expensive to get replacement parts..a lot of it will hold its value pretty well even with a decent amount of use. I would be okay leaving flak 2’s, double edge or other more current styles in a car, but the excessive heat isn’t good for anything though