Whenever I'm driving and am caught behind someone who has an ample gap in front of them and won't make any attempt to make room for me, I consider them a d1ck.

I have never been held up in my car by a cyclist who refused to make room, because I don't drive so much, and cyclists are not too frequent. But as a cyclist I often make way for behind-right-turners, because if I didn't I would feel like a d1ck. My goals when cycling are to: 1. not die 2. get where I'm going 3. communicate to cars that I (and by implication other cyclists) am willing to hold up my end of the social contract of Sharing the road. I.e. not be a d1ck.