Your best defense is to keep potential thieves from knowing there's anything to steal. Make a cargo cover for the back end. Other than that? Practically the entire car inside is plastic so good luck making it Mosler.I am the proud owner of a brand new used Element ('08 EX AWD, certified, 10K mi)! It's a great car and I'm loving it already.
I've been lurking on this forum for a while now, lotsa good information.
I would like to keep some gear in the E all the time, and I'm not sure the best way to do it. If it were a pickup I'd bolt a toolbox in the back. If it were a car I'd use the trunk (and disable the internal trunk release, so you couldn't open it without the key). I'm thinking about 3 backpacks worth of food, water, clothing, tools, etc. How can I store gear in the E so that it would take more than a rock through the window for someone to steal it?