Outer layer shape: The outer layer shape is used for the left and right walls of the car body. Click this button, then click on the drawing paper to define each corner of the shape. When done, double-click to finish.
Inner layer shape: The inner layer shape is used for the middle of the car body, and provides a round chamber for the spring. Click this button, then click on the drawing paper to define each corner of the shape. When done, double-click to finish.
Non-drive axle location: If the car is a rear-wheel drive or front-wheel drive design, you can choose the location for the non-drive wheel. Click this button, then click a point on the drawing paper where you would like the axle to be located.
Add a weight: Sometimes it is helpful to add weights to the car, to improve traction. Click this button, then click on the drawing paper at the point where you want to put the weight. You will then be asked how heavy the weight is. If you give the weight a negative value, it makes the car lighter, as if material was removed.
Remove a weight: Weights that have been added can also be removed. Click this button, and then click on the weight that you wish to remove.
Rear wheel drive: A rear-wheel drive car has a single spring driving the rear wheels. The front wheels spin freely. A rear-wheel drive design tends to have better traction than a front wheel drive design. Click this button to make your design rear-wheel drive.
Front wheel drive: A front-wheel drive car has a single spring driving the front wheels. The rear wheels spin freely. A front-wheel-drive car tends to go straighter, but has less traction than a rear-wheel drive car. Click this button to make your design front-wheel drive.
All wheel drive: An all-wheel drive car has two springs, one driving the rear wheels and the other driving the front wheels. All-wheel-drive cars tend to be more powerful than single-spring designs, but the front wheels often fail to gain enough traction. Click this button to make your design all-wheel drive.