complete car security

My commercial vehicle seems to be a target to wanna be theives (I have nothing inside my vehicle worth stealing). 

I have seen anti-glass break security films, specialized locking valve stem caps, locking gas tank caps...however, it just deters the vandal from doing the basics, breaking the glass completely, flattening my tires, pouring sugar in the gas tank...but it doesn't catch the vandal in the act, or prevent them from doing any act of vandalism in the future.

Any suggestions on products that might be available that I haven't seen through google yet?

The only answers in my experience are to keep a large hungry German Shepherd around the vehicle or as a builder in London requested, 2 x dual zone proximity sensors with the outer levels set stupidly high and screw the neighbours!

N.B. Forget about hungry Sheps, my well-fed Alpha males in car with windows part open made the best interior sensors going.