Once your wheels are in place, the next step is to put the car on the ground: draw the line between the wheels. From there, you can start to build up the outline. Designers and engineers talk about the “Y zero section”, which basically means the silhouette. It is very iconic in the case of the 911. Sometimes you’ll find the silhouette and the wheelbase don’t match, and you have to think about moving the rear wheel but that’s no problem: that’s why we have erasers.