So I am riding along in the bike lane, approaching a red light where there are cars lined up. I pull up next to a shiny new Mini Cooper as I stop at the light, and PING!. My front tire hits a piece of loose gravel, and it shoots out like a bullet from under the tire and hits this guy's door. I am quite sure it at least chipped his paint, if it didn't leave a small dent. He looks over at me with a PISSED OFF look on his face. I just shrug, and look behind me and frown, hoping he'll think it came from that direction.