Toot-ette's Syndrome

I am convinced some vehicles suffer from Tourette's Syndrome. What else explains the tendency of some automobiles to keep honking from behind?

Earlier today, I was cycling along with friends down an empty road when an auto started to talk dirty from behind. Moving from our left lane to the non-existent ultra-Maoist lane off the road, the auto went past. With a honk. What's more, it travelled down the road intermittently spewing *b(l)eeps* at no one in particular. What else than Tourette's?

This impression is further increased by the fact that drivers of these renegade motors give you a hapless look - the "how could I be so rude as to honk at you unnecessarily?" version. Their vehicles must be taking them for a ride.