The physics of the cars in the game change for vehicle-specific missions.The basic strategy is simple: Miss everything, don't let your car come more than about fifteen degrees off its line, and never, ever let your car take to the air.
This course is the epitome of everything that is wrong with GTA San Andreas. Remember this, and remember to brake as well - there are some tight 90 degree turns - and you should soon be in the lead. In the start, stay behind the other competitors, and whenever there's a hustle, steer clear of it and take over some of them.