idea's anyone?

some useless (possibly not wholly true) cunts broke into my car last night. i say broke in, but unlike last time, they didn't break anything.

i distinctly remember locking the glove compartment and the door after getting out the car (for reasons i shall not bore you with).
this morning i got to my car and the drivers door was not firmly shut. weird i thought. then i see the few items in my car (mostly rubbish) was strewn around over the chairs and the floor. the glove compartment was also wide open. the only thing that was taken was a bit of cash which i leave in my car for meters etc. radio was not stolen but there was nothing else of value in there.

i'm currently working under the assumption (i've always wanted to say that phrase) they somehow picked the lock of the glove compartment (and hence maybe not completely useless since lock picking requires some practice) and if they did that, then possibly the door as well? either that or the old coat hanger or doorstop trick to get in.
at least nothing was smashed. i am almost grateful nothing was smashed and then remember i shouldn't have to be grateful that the people that broke in didn't also smash it to pieces.

so now i plan to strike back. i have decided to come up with some ideas to booby trap my own car should anyone gain unauthorised access. it will be necessary that the trap should be quick for me to disable each time i get into my car. most important will be that i remember to do so! (i don't hold out much hope here so a non lethal trap is probably best).

i'm a little out of ideas at the moment, if you have any, please write them below!