The 1/4000 is the time the shutter stays open, not the time between pressing the shutter and the shutter opening/closing
On my fuji i just use continuous auto focus and focus on the spot the car will come into, then follow the car and take the picture.
__________________
Canon 40D (350D backup) - EF-S 18-55 - EF-S 17-85 - EF 100-300 - EF 50 - Canon 430 EX || Speedlite - Canon BG-E2N Grip
Adobe Photoshop CS4 Extended
AX-10 Crawler - Thats all I have left!!!