You Can Tell a Finn's PSA below about headlights in poor visability situations got me thinking, what can I not stand about other drivers' habits?

For me, it has to be people's failure to maintain lane discipline on the tight, twisty, two-lanes in New England.  I want to hoon (responsibly, of course) with a nice country drive and instead, I'm fearful of mechanized death around every blind corner because some clown can't keep it on his/her side of the road.

What say you, Oppo?