re: "All logo'd vehicles. Cable repairmen, private contractors, plumbers, painters, any vehicle identifiable as part of a business seem to always drive well above the speed limit, tailgate, and cut me off when I'm driving. Perhaps it's because they drive so much as part of their work that they become overconfident motorists, willing to reduce their (and everyone else's) margin of safety to nil."

ABSOFREAKINLUTELY!

I would add that in my area the occasional a-hole are in jeeps; pickups and mustangs are are usually young men between the age 20 - 35

but by far the biggest abusers have been men driving small service vans