That strange little gap between the two cup holders looks like wasted space, but it can actually serve a practical purpose. Cup holders have to accommodate bottles, cans, coffee cups, and travel mugs of different shapes, so manufacturers often leave extra clearance rather than creating two completely isolated circles.

One particularly useful reason for the opening is a mug handle. A coffee or travel mug can sit inside the circular holder while its handle extends through the open section. Without that clearance, many handled cups would sit awkwardly or simply would not fit properly.

The opening can also make it easier to grab a drink. When two large cups are sitting next to each other, the extra space provides more room for your fingers and prevents the containers from being squeezed tightly together. It also gives manufacturers more flexibility when designing holders for different container sizes.

Those raised pieces inside the holders have another job: they help stabilize smaller cups and bottles. Similar flexible cup-holder tabs are specifically designed to press against containers of different diameters, reducing movement, rattling, and the chance of a drink tipping while the vehicle is moving.

So the mysterious gap isn’t necessarily a secret storage compartment at all. Its most useful function is providing extra clearance—especially for mug handles, different-sized drinks, and your fingers when removing a cup. The exact design varies between vehicles, but that odd-looking space can make the cup holders considerably more versatile.