A GPS enabled radar detector incorporated in a general purpose navigation device dynamically handles radar sources based upon previously-stored geographically-referenced information on such sources and data from the GPS receiver. The detector may ignore detections received in an area known to contain a stationary source, or may only ignore specific frequencies or may handle frequencies differently based upon historic trends of spurious police radar signals at each frequency. Notification of the driver may take a variety of forms depending on the stored information, current operating modes, and vehicle speed. The device includes navigational functions as well. In one embodiment, the detector uses a transparent touch screen and a readily aligned mounting.