By vehicle make and model if you like.
My vote is for any Subaru.
Depends on where you're at.
On the Oregon coast (US 101) I'd say motor homes and full size trucks pulling large camp trailers. Most of them are driven by little old grandpa types who have no business behind the wheel of anything, never mind one of those behemoths. They have no place to go and no time to be there, nothing better to do than spend their last moments on earth making others late.
Not sure I'd say Prius. In an oddly ironic way, those sonsabitches seem to drive faster than a lot of sports cars here. (Thinkin' it might be a form of "compensating.")
I suppose it wouldn't hurt to mention the occasional farm tractor waddling up the road holding 30-50 cars back 'cause there's too much oncoming traffic to pass.
