I'm having a hard time picturing a situation where a bike would be completely trapped. Unless you're riding a full dresser, you should be able to take off between the line of cars. You do leave a bike length or two between you and the vehicle ahead, right? Still, it COULD happen.
If someone is able to sneak up on you so quickly you don't have time to get off, you need to work on your situational awareness. When you see the threat, don't worry about the kickstand unless there's time to put it down. Step off the bike on the opposite side to the threat and let the bike fall toward the threat (scratches can be fixed) and take a step or two backwards, thus putting an obstacle between you. At this point, I would start yelling, "Get back!", "Get away from me!". If nothing else, it will get other people's attention. If he moves to step around the bike to get to you, I would think you'd be on solid ground to draw your weapon - you can be pretty certain you're under attack.
Every situation is different, so your mileage may vary. I just tried to work within the terms you set.
Edit: If, instead of pressing the attack, he goes back to his vehicle, let him. If you can safely get the license number, that's good. If not, then let it go. If you pulled your weapon, stop as close as safely possible and call 911 to report it. You don't know what he might call 911 and say. He had a lot more opportunity to get your license number.