Hey Bob! I was just reading your latest column about the ABS problems your are having with your Z3. I had a similar issue with my 1997 M3 that turned out to be the Brake Pedal Position Sensor. I believe that the Z3 has the same setup. It lives next to the brake fluid reservoir and tells the ABS computer how far the pedal is being pressed. The thing is pretty simple. It is just a rod attached to a slide potentiometer that moves in and out when the pedal is depressed and released. The problem is the solder connections between the small circuit board inside and the electrical connector tend to fail. You can get a new one for around $100 or in true Hack Mechanic style, you can take it apart, re-solder the connections and put it back together. Hope this helps. Steve P.S. - Loved your book!