I've only had 3 encounters over the entire year.
G37 that was being a douche on a double lane onramp. Wouldn't let me pass him. My sister-in-law insisted I "not let him beat me."
C6 vette - pretty much dead even. I'm stock, so I kind of expected it.
GT350R - They really have very little torque so I got a good lead on him at first but he pulled up on me after that initial jump. We stopped playing around and just gave each other a thumbs up. Again, I'm stock.