i have a b&m shortshifter and i used the stock c-clip as well...the one that came with b&m probably would have worked fine..but the stock one seemed tighter to me so i used that.
it's been about 6 months now or so and no problems at all
and yes, you can get them at the dealer..it'll prob run you about 50 cents..or you can go to a hardware store and just match it up. same difference