The small gap between many car cup holders is actually made for cup handles — especially mugs or reusable travel cups that have a side handle. Instead of forcing the handle to press awkwardly against the wall of the cup holder, the narrow space gives it somewhere to sit.
That is why the shape often looks oddly specific. It may appear like a random break in the plastic, but it helps a mug sit lower, straighter, and more securely. Without that gap, a handled cup could tilt, wobble, or simply refuse to fit properly.
It also solves another small problem drivers rarely think about until it happens: movement. A cup that does not sit correctly can shift when the car turns, brakes, or hits a bump. The gap gives extra clearance and reduces pressure on the handle, making the cup easier to place and remove.
In some vehicles, that space can also work as a flexible divider between two cup holders. It allows slightly larger bottles or oddly shaped containers to fit better than they would in two completely separate round holes. So while it may look like wasted space, it often adds usefulness.
The funny thing is how invisible this feature becomes. Drivers use the center console every day, but because most modern drinks come in bottles, cans, or handle-free cups, the purpose of the gap is easy to miss. It only makes sense the moment you place a mug there.
So no, it is not a secret compartment, a hidden coin slot, or a forgotten piece of plastic. It is one of those quiet little design choices that only seems strange until you learn the reason. After that, you will probably notice it in almost every car you sit in.