Where you mount the Cobra 3865 changes its personality. The official manual suggests "center of windshield." The Exclusive Manual has three specific mounting philosophies:
Use the Internet Archive’s Wayback Machine. Input www.cobra.com/support/manuals/3865_exclusive.pdf. Look for snapshots dated between 2006 and 2008. These often contain the full, original PDF. cobra 3865 manual exclusive
Join communities like RDForum.org or RadarDetector.net. In the "Vintage Detectors" section, search for a user named "VortexRadar" or "BridgeCreeper." These long-time members have archived thousands of manuals. Post a polite request for the "Cobra 3865 exclusive" – do not ask for a standard manual. Where you mount the Cobra 3865 changes its personality