Someone was able to break into my van by prying the door open with a
crowbar from the top corner.  The damage is not huge, but there is bent
metal.

What is the best theft deterant I can use?  An alarm, a big sticker, a dog
:-).  All that was stolen were my glacier glasses and my regular
sunglasses (luckily the didn't take any of my  mountaineering and climbing
gear!).  I really don't want this happening again, what can I do!

Thanks

Gregor