Oh I'm all over this one!
In sunny warm weather, I play stuff like Weezer, Green Day, Rage, Korn, Offspring, upbeat Beck, STP, Franz Ferdinand, Gorillaz, Black Crowes, DT, heavy Porcupine Tree, etc.
Oasis Definitely Maybe and Be Here Now are good summer albums
When it's 90+ I bump gangsta rap with the windows down!