I started heel and toeing in my old mr2 after I locked the back wheels entering a corner on a trackday. I was slowing for a corner and braking hard, I changed gear and managed to lock up the back wheels. I put it down the differential between the current revs and the New revs. It also makes the gear go in easier if the revs match. With heel and toe I haven't experienced the problem again. Also it sounds cool and is fun