It's not that sort of aggressive though. I would agree with your reasoning, but here, they aren't aggressive enough to try and pass you when you're first, but if they take a corner too wide, and then try to correct themselves, they will power straight through you to get back on that line. Usually happens in the middle of the pack.
you can use Microsoft Points to buy games off of Games on Demand. When you go to the page were you buy it and it tells you how much space it is, you can press y(says so on the bottom) and change to Microsoft Points.