> Well, I suppose you could substitute a dual-spray "thief-cleaning" "solution"
> by having one spray bottle filled with an ammonia-based cleaner, and
> the other with a chlorine-based one.  The switch would trigger spraying
> from both sources.
> 
> For those who wish for a more passive attack, you could just install one
> of those disposable cameras to take mug shot of the "alleged" perp.
What about a valve that directs co into the vanagon complete with a 
video recorder snapping the last moments?