That is a point well taken. One of my biggest fears is having the truck out and running into a problem like a bad coil. I'd like to hear some other stories about people who have left their ignition switches on, and the effects of it, other than two dead batteries. I've decided to print a little note "TURN IGNITION SWITCH OFF!" and put it on the inside of my drivers door, where it's the last thing I see when I exit the truck. I've always been good about turning it off, but now I'm paranoid!