Today, many high-end car manufacturers, such as Mercedes-Benz and BMW, are incorporating special tints into their windshields to protect the interior look and comfort of their cars. Unfortunately, this creates a very real problem for people who own portable radar detectors.
Putting tint of any kind on your windshield that contains metal film is essentially like putting a blanket over your radar detector. While radar microwave signals can still travel through fiberglass, plastic, and glass, they cannot penetrate metal. Some tints are worse than others, but if it contains metal of any kind, it will reduce the performance of any portable radar detector mounted inside the car.