I found a few sites but I don't know if they're outdated. Based on those websites the following states don't allow radar detectors, please correct me if I'm wrong or missed something.
D.C.
Virginia
New York - Bill Pending
North Carolina - Bill Pending
Minnesota - Not regulated, BUT - hanging things from windshields not permitted. (Hmm. Wonder. Does this include rear-view mirrors, too?)
D.C.
Virginia
New York - Bill Pending
North Carolina - Bill Pending
Minnesota - Not regulated, BUT - hanging things from windshields not permitted. (Hmm. Wonder. Does this include rear-view mirrors, too?)