It will work with the Mach stuff. The right harness has to be aquired for it. It has to be the harness that will switch on the rear amps. That was the big problem back in the day. I did eventaully end up getting rid of the Mach speakers. They just sound so horriable. Just my personal opinion though.
Um... security... Well some guys have picked up a stock double din radio out of a junk yard, removed the face plate of it, expoxied the old buttons and just slipped the face plate on at least to deter theives looking for an easy target. But there are no security features on the deck itself. Most of the double dins don't have anything like that though.