Some suggestions:

- get your friends to add their cars to the site, and make sure they use your code on the forums they frequent (I'm assuming that you link back to modslog)

- make the value prop clearer: add a car, share the details online. It doesn't jump out right away on the front page

- show how the auto-generation works, even if it isn't your car. I wanted to see how this worked, but I couldn't on the only car in the system

- somehow surface the name of the owner of the vehicle, and make a garage-centric view of cars. You want narcissistic users to be able to make garages and show it off to other people.

- fill out your sample car more - e.g. why is statistics, events, and m&r not filled out for your sample car?