Maybe it's a demographic of certain cities, because the list does hold true for the most part to the Phoenix area, except there are a few things to take off and a couple to add to the list. I'd subtract the Cobra, EVO, and STi/WRX douches from the list, as I don't see nearly as many of them during my daily commutes as I do the following...
GIXXER GEEKS: Bullet bike douchebags rank high on my list of most-loathed genetic deviants on the road. Being that Arizona has no helmet law (just mandatory eye protection ... such as sunglasses, heh), 75% of these douches zip through traffic all hunched over like they're humping the fuel tank, randomly doing asinine stunts like gunning wheelies and darting between cars with inches to spare. They always seem to be sporting buzzcuts and Oakley sunglasses that bear a disturbing resemblance to those of Vanilla Ice (who may have popularized the crotch-rocket culture with his neon-yellow toy bike in the long-forgotten "Cooler Than Ice").
HUMMERHEADS: The "I'M IMPORTANT!" people (primarily drivers of grossly overpriced SUV's and minivans) that feel there just isn't any way to cope with everyday life without having a cell phone and one hand glued to the side of their head, farting around with their radio controls with the other hand, and making a half-conscious effort to try to steer with their knees. Their lack of vehicle control and delusion of self-importance is exacerbated by their uncontrollable need to tailgate anyone not doing 15+ MPH over the posted speed limit (double that if it's in a construction zone), and/or to cut off everyone they pass with sudden swerves that usually involve crossing three or more lanes of traffic in one go. Turn signals must be optional equipment on these vehicles ... or it's impossible to free up a limb to operate the lever for one, given everything else they're doing beyond "driving."
ALMOST-ANGS: The aforementioned V6 Mustang owners, primarily those of the 99+ to present models (when the V6 equaled/exceeded the stock ratings of early 80's V8 Foxes). They couldn't afford a real Mustang due to exorbitant insurance costs - a rash of tickets for speeding and reckless driving for prior douchebaggery will do that - so they settled for two fewer cylinders, one less tailpipe, and twice the implied free license to act like a complete douche. Aside from standard-fare douchehood hijinks like mindless speeding, obsessive tailgating, and IRL-style lane changes, they're usually almost as bad as (if not worse than) the typical hardcore Honda ricer when it comes to wannabe tack-on "go fast" goodies. Y'know, things like stacking wings upon wings, fartcan exhaust tips, racing stripes of hideous color combinations (I've already seen dark green stripes on a yellow '06 model), five pairs of foglamps/driving lights, faked-out dual exhausts that sound like an F-body with a rotted-out
Flowmaster, and so on. I've yet to see one actually try to take someone at a stoplight race, though, as they apparently know well enough that they'll likely get stomped by a great many other cars out there (namely most V8-equipped Mustangs) and they wish to avoid earning that one last reckless driving ticket that will finally get their insurance policy canceled indefinately.