On www.just-cars.co.uk forums, they have this and thats where Kevin got the idea.

Anyway, what you do is you post a thread with a picture of a car in it (could be whole car, outline, etc.) and members post their guesses of what they think the car is. After someone wins that thread is locked and the winner must start a new thread within 24 hours or either myself, another mod, or Kevin will create a new one. ONE THREAD AT A TIME, or it will be deleted.