I need someone to educate me on this technique. I was fortunate to be at Lime Rock a few weeks ago for a wonderful track event sponsored by the BMWCC of CT. If you've never tried it I highly recommend it. My concern is that coming down the straight and into the turn I would downshift and every time the wheels would chirp (an awful feeling that I am damaging the vehicle). My instructor, who was beyond excellent, explained the concept of double clutching and heal toeing. I have been trying to perfect my technique ever since. However, I have come to realize that on normal roads, and in the constraint of legal speeds, the car shifts just as well when I don't double clutch as when I do. I know it is the marvelous german engineering in my M3 at work, but it didn't it work at Lime Rock. How does the car compensate for the spin down and how much of an rpm differential can it handle? Should I double clutch always, regardless? PS - As for heel toe I am helpless. Any hints on how to do that crisply?