Also, being in a stopped vehicle is in many ways worse than being on foot. For one, you're trapped, and in this instance, your vehicle is drastically smaller and less powerful... I doubt the OP could have easily gotten away unless he went Tokyo Drift on this guy, sliding under 18-wheelers and stuff. Those big trucks are pretty quick for their size, I've raced a few. I also don't think it's possible to get away from a determined attacker in a vehicle while sticking to the laws about signalling and "safe" speeds, thus putting you, your passengers, and everyone else on the road at risk.
I'm all for giving people the benefit of the doubt, but I'm not going to make excuses for people who don't need them, especially if I have friends in the car with me whose lives I'm responsible for. Too bad for everyone else in that idiot's truck, but if he cornered me they would be fair game.
Choose your friends wisely or you might get shot while they're trying to run people over.
EDIT: I also wanted to point out that I didn't understand the OP to be wishing he had his gun so he could shoot, as much as he felt like he was crippled in a way during a stressful situation if it came to that point. I have felt the same way when I was on crutches where I was painfully aware that I didn't have 100% of my resources available to me when a situation got uncomfortable. No, I wasn't about to kick anyone in the head just yet, though lacking the ability to do so effectively if needed really bothered me.
