Some ideas on how to develop physical self-defense skills in highly restrictive circustances, such as when you are seated in a car, train or airplane.
The video demonstrates the ideas with combatants seated next to each other. It is important to train other positions as well, e.g., one person standing, while you are seated (in the car, or in a subway), being attached by people seated in a row behind you (e.g., in a train, airplane, or car), etc.
For those who practice the kata Naihanchi, you will recognize some bunkai straight out of the kata. (Of course, you can apply other kata in this situation as well.)
For a deeper explanations of the physical self-defense fighting concepts in the video, see http://www.fullpotentialma.com/self-defense-combat-inside-a-car-bus-train-or-airplane/