Perfect Car Proportions Explained With German Hatchbacks: All About the Wheels

But what are proportions and why should they influence something built to go from A to B? Well, it turns out drawing a car is a lot like drawing a person or a cat. You need a point of reference on which everything else "rests".

For a person, that point of reference is the head - the height of a human is generally between six and eight heads. For the car, the wheel fills the same role, dictating the height or length of the vehicle.

You may have seen a post on Instagram showing circles on a BMW, Audi and Mercedes. We tracked it down to the car designer Berk Kaplan, who uses three modern German hatchbacks to make his point.

More specifically, there's the Audi RS3 Sportback, the BMW M135i xDrive and the Mercedes-AMG A35. At first glance, these are three completely different machines, but they actually play by the same rules for how a compact hatchback should look.

For example, the distance between the wheels is roughly three circles wide while the height of the hatch is roughly two wheels to the side windows or 2.5 wheels overall. Make the wheelbase longer and it looks like an economy car. Raise the roof and you'll get a dorky minivan.

You may not realize this, but other elements are also anchored by the wheels. For example, you can draw a line through the windshield that touches the front tire and generally ends at the bumper.

The placement of the lights isn't random either. On all three of these German compacts, the headlights are in line with the horizontal line over the top of the tires while the taillights sit one headlight higher. Generally, this rising character line is where the door handles are located as well.