It's no Viper, but I've had some erratic behavior around my C5 out here. Most of it the standard stuff and a rare swerver, but there was one guy who went NUTS on me.
I was driving down to New Haven on a rainy Friday afternoon, got off Rt 15 and heading down Whitney Ave which has two lanes in either direction. I get to a 4-way light by a Dairy Queen and a Mobil station behind a beat early 80s chevy pickup. We wait for the light and when it turns green this guy brake stands it in front of me. Nothing hitting my car, but my first thought is what an [******] this guy is. At the time, the car was new and I was absolutely ANAL about the black paint. So he goes and I let him get a good 10 cars out. Now he starts slowing down. I slow down. He puts on his left turn signal from the left lane as though he's going to turn off. I go to roll past and he cuts the wheel right. I just brake and let him go. This behavior continues until the next light. Now I'm really PISSED at this guy and I try to position cars between us. I'm not too concerned by him yet, but definitely want him screw off.
Just my luck, the car between us decided to turn off. So now it is the two of us behind a pair of cars. For a short distance there is no problem, then he SLAMS on the brakes whilst cutting the wheel into my lane. I was still in 2nd, so I punched it, crossed the yellow line (no traffic here on curve w/ high visibility). Now he's behind me and I think in my head "go ahead and hit me, [******]. I'll own you" But this is when he gets really nutty. Now I am boxed into traffic and I am in the slow lane. I'm trapped and he's behind me. Keeps gunning it like he'll hit me and then braking when he's a few inches off my ass. I'm tensing up now, but it gets INSANE when he yanks the wheel right and hops the curb onto the SIDEWALK.

Now he is beside me DRIVING ON THE SIDEWALK and swerving at me. He is getting 2-3" off my mirror before pulling away. I have nowhere to go. Can't go left, there's a car. No turn-off for another couple hundred feet.... and he's on that side anyway. Can't punch it and disappear because I'm still behind traffic. If I brake, then I'm stuck behind him again. So I bite the bullet and stay right on driving as best I can in my lane w/out moving. At this point I expect him to hit me since he finally DID intend to hit me. I tucked up TIGHT to whatever car was on my left and was out of room, he was still 2" off my mirror, then he swerved back to the sidewalk. I'm still responding calmly to what's going on on the outside, but adrenaline is now switched to 100% and I'm racing a mile a minute in my head.
We come to a light and I'm STILL trapped behind traffic. He has since pulled back ONTO the road and pulls as tight as he can to the back of the C5. I didn't have my permit yet at the time since I had just turned 21, so no .45 for backup. I'm eyeing my mirrors waiting for him to get out of the car or something while I reach behind the seat and rummage for any tools I could use on this guy.... for once, I actually don't have anything in my car. So instead I "pulled back the slide and chambered a round" with my trusty Swiss Army Knife (never leaves my side). I had one of the accessories out and used it as a "trigger" by which to hold the knife. I did all of this in motions that would make it obvious what I was doing....if I had a gun, but he couldn't see whether I did or not. At least not clearly through the back window. Whether he thought I did have a gun or that just happened to be his turn, when the light went green he went right and I continued on to Karen's place where I phoned the PD and gave them a description of the truck (which had no plates). From there we went out for happy hour. She drove.
That experience freaked me out a bit. Everyone asks me if I provoked the guy because they think it is as incredulous as I do that someone would do this, but all I did was get stuck behind him at a light. Must've been the Friday after a ****** week for him, who knows?
And by the way, the 'ol Swiss Army Knife would have served well if he had come after me. The "trigger" piece was a pointed pick or needle-like extension based off the center of the knife. With the knife palmed in my fist it would have made one MEAN impression between my knucles.
Final analysis: except for the spot where I HAD to swerve to get out of his way or get hit, that was as close as he came. I don't know what wire snapped w/ this guy, but if he was SERIOUS about hitting me he could have. I thought he was posing and being a dick until he popped the curb. THEN I had to take it seriously that he probably intended to hit me. The whole incident between the light at Dairy Queen and the light at the Post Office took roughly 1 minute, maybe more, over ~1/2 mile of road. Thankfully, it turned out to be nothing more than a stressful stretch of road and a story I can tell with some vigor. The police never got back to me about the truck and I can only assume that they probably didn't look too hard for it.
