The STFU Guys Pot Brothers at Law® on Instagram: "Yes, radar detectors are legal to use in California, but there’s an important catch. You have to be careful how you use them. You cannot mount a radar detector on your windshield if it obstructs your view. If it blocks your vision, that can get you stopped and cited. Mounted correctly and not obstructing your view, they are legal in California. That said, laws vary from state to state, so Google your state before relying on one elsewhere. Know th