I like shooting with clouds, but I just find clouds to be interesting.
I mostly shoot my car and my friends cars, Im kindof obsessed. Some good tips there (including the intro of course. Weird angles I think is key, Turning hte wheels to show off the rims is whats up, I usually dont bring a ladder and just use my/someone elses car as the ladder, and I envy you for having a wide angle lens!!
Also, dont be afraid to get down and dirty for the shot hehe
EDIT: Also, what settings do you usually shoot at for rolling shots? I usually just mess around until I can get a few good ones.