Americans spend a lot of time looking out the windshield of our cars. Ever wonder what those little black dots are about? They’re called Frits, by the way. Are they there to be decorative? Sort of, but they serve an important purpose. Frits are enamel baked into the windshield glass.
The windshield is bonded to the car’s frame with a urethane adhesive. It’s imperative that this bond be totally secure. The frits serve as a secure contact point between the glass, adhesive, and metal frame of the car. They become smaller as the pattern spreads beyond the car frame. This is done to make them more aesthetically pleasing. So, yes, they’re decorative, but that’s not their primary function. Without Frits, your car windshield would leak.
Source: motorbiscuit.com