Advanced warnings (a warning in time to do some good) are more likely if one can avoid some problems caused by the low mounting position. Advance warnings require the greatest possibility of receiving a weak fragment of the beam while it is being used on traffic a good distance ahead. To maximize reception of weak signals, one must reduce blockage and interference.
Mounting high on the windshield will position the detector to "see" through the windows of most vehicles ahead.
Glass in vehicles ahead is a good thing for your detector to see; it can scatter reflections in your direction. Sometimes it develops a glow, or a bloom, when the beam strikes, giving yet another chance for advanced warning.
Mounting high on the windshield reduces the effect of sunlight reflected from the hood, which increases the detector's ability to find weak beam fragments.
Daytime warning sensitivity is completely dominated by how one manages the sunlight issues.
Mounting high behind the tint band may reduce the laser signal somewhat, but it reduces the sunlight contamination by the same amount. The result is an unchanged laser-to-sunlight ratio from the scene beyond your vehicle, but with reduced hood reflections owing to a higher vantage point—a net gain. Only in the dead of night would a just-below-the-tint-band mounting position be beneficial.