I have had the XTR-690 for about a month, and already exchanged it once. Although I usually put a sunshade over my car window during the day, or cover the detector with a hat so it does not receive direct sun, the display loses its normal bright blue background and it is almost impossible to read in the heat of the day. Over night, when the radar detector cools down, the display becomes normal. Meanwhile, all the sounds work and the detector works (very well) even though the display becomes difficult to read in the heat. Has anyone else experienced this display problem?