tornado 101

I'm about to head out to a part of the world where there's been a lot of tornadoes lately. Most likely I'll never encounter one, so that possibility is covered. But what about the other possibility, that by chance I do? I know what to do during an earthquake (and often enough have done it), and hurricanes move slowly and usually allow long warnings that they're coming, but aside from a few dust devils in the Central Valley I've had no encounter with tornadoes.

Let's say I'm driving along in my rented car, and there's been a tornado warning on the radio, and off in the distance I see a tornado. What am I supposed to do? How do I stay out of its way? How do I know what direction it's likely to be going? What do I do if I can't get out of its way? What if it's behind me, and it sees me before I see it? What if I'm not in my car, and there's no other people around to follow?