I'm actually trained in how to respond to an accident involving injury. Even still, unless I saw fire, I would never move a person involved in a car wreck by myself. It is too much of a risk of further injury. Cars in movies explode because of special effects. You know like the ones that make them explode when you fire a few shots into them. The reality is that cars are more likely to burn up than to blow up. Unless there is fire, the car isn't going to magically blow up(though this may change with hybrids and the large battery packs...). You have at least enough time to wait for emergency personnel and the sizable amount of rescue equipment they carry. Very few people carry neck braces and back boards with them in their personal vehicles...
However, if you do see fire, the game changes dramatically. Absolutely pull them from the burning vehicle. Preferrably with the assistance of another person, so you can hopefully prevent further injury. Sometimes it is unavoidable.
Unfortunately I have had similar situations to mimartin. The worst was getting there just a few minutes too late.