Practice taing shots of cars on the motor-way, this is good for getting your reaction time up to speed and tracking a moving object, you don't even need to take a photo but try and get your centre focus point in one spot and move with the object trying to keep it in the same place, then its just a question of doing the same thing but pressing the shutter release at the same time.
A few years back i shot rocket drag cars at Santa-pod Raceway, these babies do 1/4mile in 5seconds, so you can imagine its pretty damn fast.