I like the air horn, but also have common sense park in a well lighted area were there are decent people around, so that if they see something not right they can call police on a cell phone , and do use a club when parking.
Dont be predictable, see things from the other persons view ask yourself is my truck a sitting duck?? each time you park it.
Wire in a kill switch, stick someting under your tire that will flaten the tire, move it out of the way each time you get in and drive forward. GPS?
At home pull in the back yard out have a locked gate, dogs, dont leave nothing on the seat or in view.
I have camped in my van when traveling and parked at the holiday inn before and had people test to see if my door was unlocked, in both cases the area was not the greatest.
