No kid in my charge would be playing with cap-pistols or hyper-realistic AK-47s with notches and fake blood spatters: either. Or listening to Kill-the-Bitch CDs, or..

But the medial digit has become as common an expression as, "so's yer old man".
Now, if you had 900 mSec to indicate to a passing glad-handing pol, your disapproval (of his platform? himself? whatever), as I see it you have two universal options:

1) Thumbs down.
2) Middle finger up.

Both the Pres and the Veep appear to make liberal use of #2, while you'd think that the refined folks in positions of Power.. might opt for the former, wouldn't ya?

See what happens when the Top is as corrupt as this particular assortment? They reinforce the tawdriness of the unwashed masses.

(Personally my choice would have been: to take Both Hands off the wheel and position my fingers in a Cross.. while Shrub wouldn't get it, maybe someone else in the car would. Might even decipher ~~ blood-sucker and -spiller! if imaginitive. OK forget that last.)

I see your point about the cheelrun and about a patina of civility to delay the warping of their malleable jelloware.. for a little while. So I'd say to the frustrated driver with a busload of kids waving at the bling-bling aspect of Celebrity:

"This gave bad impressions to your charges; impressions of adult contempt for a putatively contemptible figurehead. You should have stifled that natural urge. You're docked x-days and get a reprimand."

I hope the union prevails. Loss of employment demands a more severe rudeness than this common digi-signal IMO. And one needn't be an anarchist to turn the other cheek, as some ancient guy used to say to an earlier flock of sheep. (But then his messages got passed through corp HR and committes) and, well - today we gots Prezs and Veeps who swear.. by the guy They Say, but still Lie A Lot, in between finger raisings. And invitations to an unnatural act, in the latter case.

So then.. ya want this driver should do better than The Rulers.. or starve next?
Guess I need to send you my Gooder Book.