GPS Head-Up Vehicle Speed Display

67% of reviews on Amazon.com give this product a positive rating.

My Jeep Wrangler has a black upholstered shroud over the instruments. In direct sunlight it is near impossible to read the speedometer! Installed heads-up unit without screen. I can read display projected on the windshield in all but the brightest...

Display is far too weak for daylight use, there is no manual adjustment for brightness, the display is completely invisible wearing sunglasses, the 'mounting system" consists of a no-slip pad that slips easily. Oh yes, also the readout fluctuates...

I got this HUD for my Camry after I almost rear-ended another car on the freeway while looking down at the speedometer. Here's my impression of it. I hope some of you find it helpful! Appearance/Construction - The device is small, light and portable. ...