Algodoo

Good job overall but there's a problem. When the scene starts, the yellow car on the right hand side of the scene jumps into the air and flips over. It does that because the car is below the top surface of the plane that is on the same collision layer as the car. You can fix that by adding another plane with a different collision layer and a lower upper surface. Also, change the collision layer of that one car so that it rides on top of that new plane instead of on top of the other plane that the other cars ride on.