I mount it to the windshield. Again, tint does have an affect on the performance and the tint at the top of the windshield will reduce it's performance. I mount mine right below the review mirror in the center of the windshield so that the rear antenna has a clear view between the front seats and out the back.

Others state differently, so to each their own, but fact is any tint on the glass you point a radar detector through affects the detector's range. This is mainly an issue on units that feature rear and side detection like the V1. Metallicized tints are worse than dyed tints.

Same with Sat. Radios...tinted windows and you'll need to use an external attenna as tint hurts the reception there too.