I think it's pretty awful, too, and I can probably count the number of times I've said it on one hand without using my thumb.

Once was directed towards a woman in an Escalade that nearly hit me with her mirror while I was in the bike lane (and put her passenger-side tires over the line to do so!), then swerved towards me again when I began to pull up next to her at a stoplight. I had to ride into the the gutter to get around her, and I let the c-word fly right into her open window