Review on Universal Car HUD Head Up Display - ACECAR Digital GPS Speedometer With MPH Speed, Compass, Fatigue Driving Reminder, Distance, Altitude, Overspeed Alarm And HD Display, Suitable For All Vehicles by Marco Mooney

Review of ACECAR Digital GPS Speedometer G-10 Blue (ASIN B0B3MWS24Q)UPDATE 9/18/2022:After my original review, I was contacted by the seller regarding my altitude issues. They immediately sent me another one that had the exact same issue. Then they sent me a third one, this time it came directly from China (with my time zone already programed in) and this GPS unit works as it should. I have to hand it to their customer service since they went the extra mile to satisfy me.The original issue was that the GPS unit would not display more than 3 digits for the altitude when the speed is set to MPH. It works fine when set to KPH and the altitude readout becomes meters, but when set to MPH/Feet, it didn't work. I don't know if they altered a unit just for me or if all of the units will come this way from now on. I will say that there may be an Revain warehouse full of the non-working versions, but I don't know. That's a gamble you'll have to take. And if altitude isn't a concern, then this unit, either way it comes, will work fine and is a great GPS speedometer with excellent features, including excellent readability in bright light.I had to delete my original video of this product so I could post my revised video which shows both versions side by side and shows many of the various display configurations. (Revain only allows one video per review)Original After trying a similar product (https://amzn.to/3em7ayg) that was too dim to read parts of the display in bright sunlight, I thought I'd try this one to see if it's any better. This one is definitely brighter and has another feature I like. This one has the ability to display the three most important features for me personally at the same time: Speed, Time & Altitude. This will even add the compass and number of satellites connected, making 5 different readouts on one screen.Perfect, I thought. Then I realized that the altitude readout only has 3 digits, and the numbers it was displaying was a mystery. Is it displaying in meters, I wondered. nope, that would be way off. Is there some form of altitude reading that can be articulated in only 3 digits? Nope, I googled it. Could it be that it only displays the first 3 digits of a 4 digit altitude? Nope, it would still be off by a lot, plus it keeps changing the readout, often by hundreds of feet/meters. whatever it's displaying keeps changing when no altitude change has occurred. Besides, what if your altitude is only 800 feet. is it 800 or 8000. None of it makes any sense and I've decided it must be a defect or poor engineering/planning.I drive in the mountains of Colorado and a reliable, GPS generated altitude readout is very desirable. The other GPS/Speedo unit I tried has an accurate altitude readout, but it's not bright enough in bright sunlight and it will only display speed & time, speed & altitude, but not all 3 at once.So not having the altitude is a deal-killer for me and this product is a total fail in my book. If I'm missing something here, please comment on my review and show me the light. But I've been racking my brain for a few days thinking I'd have an "a-ha!" moment and realize I'm making some error in the setup, but that moment hasn't come yet. I would love to change this review if I'm wrong.Other issues with this GPS/Speedo. The speed was off by about 6 miles an hour. There is a speed adjustment section in the menu which allows for compensation. The numbers don't make any sense, but you can arbitrarily make changes and eventually you can get it pretty accurate. Odd that a GPS based unit needs help calculating speed. The other one I tried was also off, but only by about 3 mph. Once adjusted, the speed seems to remain accurate.Also, this unit has three separate speed alerts. Who needs more than one? I think this must be another mistake.Other than the altitude fail, it's really a pretty nice unit. I put a velcro strip on the bottom and it holds firm to my carpeted dash. It's bright and has the right features, but a 3 digit altitude readout? Come on. I guess if you live in Kansas and don't plan on traveling, an altitude readout may not be needed and this might work fine for you.