The small emergency fire extinguishers are good for would-be car jackers.
Locking your doors helps too. Unless they have a hammer... in which case I'd be trying my best to put my fronts to full right lock and stepping on the gas.

Of course bright ideas don't always come to fruition when you're caught by surprise.

edit: ACE: one would assume the sword would be of the decorative type. A Katana set or perhaps a geeky fantasy sword.

__________________
[I]trolololol[/I]