During the August 13 show a caller asked about the horrible grinding noise when she tries to start her car. The problem was diagnosed as bad teeth on the ring gear.
Here’s a solution that works for me in my Mazda MPV, which has the same problem: Before turning the engine off, I put the automatic transmission in gear (I prefer #2). This causes the engine to stop in a different position than it normally does, so good gear teeth are available to the starter next time. Works like a charm!