Microsoft points

1. Go to the website: http://www.dreamcarchallenge.com/main/Default.aspx
2. Hit the Enter Challenge button on the right of the page.
3. Just hit "Next Step" on the bottom right, until you reach the end (or you can take the time and customize the car if you want...)
4. Fill in your info on that next page, IMPORTANT, here is where you select your option to receive the Free points!
5. Make sure you check the 3rd box from the top that says "Yes, I would like to receive Microsoft Points by participating in this promotion. Tell me more about Microsoft Points."
6. Submit your entry and wait for the email with your point code.
7. You can go to http://points.microsoft.com/ and add the points there without having to sign-in to your xbox live.

I've tried this and it works. People have said they can do it multiple times, by changing the email address. If you've got multiple email accounts, then it's worth a shot. I've only done it once so far. Email w/ promotional code arrived instantly.