I'm pretty sure they do it because that is what the car wants to do. They can fight it but he car wants to head down hill coming out of the last corner. Then as they get on the flat they can start to set the car up for the next corner. I think it is the fastest way around the track even if it doesn't look like it. If you tried to hold the car up against the wall coming out of the last corner you would have a fight on your hands. The car wants to head down to the inside and it won't want to go back up until it gets settled.