Securing the Vanagon Westie Cabinets is pretty simple.  Just install a
locking cabinet latch in each door.  Keyed the same they provide a modicum
of locked security sufficent in most states for storage of your favorite
personal protection device.  A hasp and padlock will lock the rear seat
area.

Non westies can have a lockable box installed on the floor or you can modify
the seat bases to make a storage location that is locked and hidden by the
carpet.

BenT, living in a high crime city like SF has lots of knowledge in this
area.