Goodness! That must have been scary!
Just goes to show, once again, it's not the breed.
We've been lucky. People here pretty much obey leash laws, and no dog has been smart enough to open a car door, here...yet. Perhaps a window down if the car was on, and the child lock not engaged would be far more likely.
Well, luck or not, we've only had the small yippy dogs try to charge (leashed) at us, dragging their owners. My girls will sit if I tell them, and calmly wait for the errant knucklehead to realize he's in over his head...usually about 2 feet away, when they notice "This dog is H-U-G-E and NOT MOVING!!"
Stops 'em dead in their tracks every time!
I don't think these unrestrained knuckleheads are deliberately singling our Rotties to go into the "charge mode." I think they'd do it because they ARE knuckleheads. Most likely they've gotten away with it before, as well.
I give NO dog an excuse! Dogs read dog language very well! Tailed or not, the charging dog can figure it out. He doesn't want to. That excuse only works for me at a distance of 100 yds or more. Untrained, unrestrained knuckleheads. You think a dog can't "see a butt wriggle in happiness?" Don't kid yourself. You think they can't see the hackles are down? You don't think they see a dog who's ignoring them totally?