Forza 2 is basically the ONLY XBox 360 game I play. I have others, but don't put in nearly as much time as I do with FM2. My gamertag is "unsulliedspy" (couldn't you guess?). My skill level is 19, not sure where you stand but I'm sure you could put up a good fight in a race. I'll have to get my XBox setup again, we can race later today.
EDIT: Wow you've got some achievements to get! Once you've unlocked endurance races the game is pretty much over, set the AI difficulty to Easy and all the other difficulty stuff way up and use a 55% driver to repeat endurance races. Make sure you are either using a wired controller or plug in with the Play and Charge kit so the controller doesn't shut itself off and pause the game. I make most of my money that way, I spend a lot buying and customizing cars.
Oh yeah, and this is my 1,000th post