Quick but true story - I drove my '69 Z back and forth from school in the early '70's, about 180 miles one way. Since I parked it on the street near the dorm (shudder, for real), I decided to equip it with a motion sensitive alarm, wired directly tp the battery, and added a short lenth of chain and a padlock to the hood to keep anyone from raising the hood to steal the battery or disable the alarm system. Driving one afternoon to the local mall, the car suddenly died, and smoke started coming from under the hood. I jumped out, popped the hood latch (like an idiot, no fire extinguisher handy), and reached in and grabbed the chain - wrong move. The chain had dangled over into the motion alarm and got caught up in the horn relay wiring, and produced a dead short to ground through the chain, It was RED hot, and burned the daylights out of me. Fortunately, when I pulled the hood open, it pulled the chain off of the terminal, and ended the short before it burned the car up. I took the chain off, the Z restarted, only damage was a couple of fried wires and blisters on my hand. Learned a lesson about unfused circuits.
The Z was parked on the street for a couple of years, I even left it there a few weekends and drove my girlfriend's Dodge home (slant 6, better mileage). Never a single problem with theft, vandalism, or anything else. Minor miracle and sickening when I think about it - really lucky.
Steve