A few years back I had to re-wire my whole front electrical system, got a new harness from ERA to do the job. I was installing a self tapping metal screw in the floorboard. As fate would have it, the stinkin' screw drilled through the floor and directly into the positive battery cable under the floor going to the solenoid. This was of course a clean, tight direct grounding of the positive cable. It revealed every possible source of grounding wire from the frame, to the headlights, to under the dash, to the motor, etc. etc. by melting the insulation off every wire that was ground. When the enough ground wires had finally burned through (I'm standing there going WTF is happening???) the current path then ran through my metal wrapped over plastic hydraulic line to my slave cylinder. Melting the plastic slave line and dripping brake fluid all over the floor. Freakin' nightmare, it slowly dawned on me what was going on and I frantically disconnected the battery in the trunk. A small part of the dash area still has a couple of burn scars (patina you might say). Oh, and the smoke got in the gauges and darkened the lens. So, I got all new cool looking gauges now too.
Me and this car been through a lot together, the bond is tight, I'm taking it to my grave with me.
Currently running the best it's ever run, awesome, I love this ride!