ACECAR Digital GPS Speedometer New HUD Car Head Up Display LCD Display with MPH Digital Speed Compass Direction Driving Distance Altitude Overspeed Alert for All Vehicle

I travel a lot for work and this thing is great!! Easy to set up. I had to calibrate it a little,but very easy to do. So much nicer to check your speed than using the car speedometer.

Worked for about 2 weeks, but the Speed was off by 4mph. Not accurate and very glitchy. Now after trying for a week to get it to pick up, it just flashes its trying to find signal.. Says it has a 1yr warranty, but no way to contact the company for that warranty info

It came default setting to mph. Simple enough instructions to set time, color, and brightness. If you need to calibrate the speed, you can do that too. Basically each setting has a numbered category. For instance if you need to adjust brightness, you need to long depress the button for 2 seconds and the scroll to category number 6, etc. and adjust it within the designated category. Just follow the key that’s supplied for which number category does what.Not sure why some reviews had trouble figuring that out.Mine matched the actual speedometer so I didn’t need to calibrate the speed at all. When you start your car, it takes less than 10 seconds to automatically connect to available satellites to start working.

I always figured there had to be some sort of device available on Amazon that would allow you to monitor how fast you were driving. This product works decent. Probably the biggest issue that I had was that the instruction manual requires a magnifying glass to read. Other than that, once I figured out how to adjust the settings I was good to go. I do find that I have to recalibrate mph I wouldn't say frequently but every now and again.

First off, reviews complaining about accuracy... you guys are lame. It will allow you to calibrate if you notice a discrepancy between you phone's GPS & the unit's. You will notice it is slower to respond than a real, non-GPS gauge. Keep in mind GPS technology is accurate to about 3 feet so that's why it'll slowly tick down when you come to a stop, for example. Or if you're clocking 0-60, this isn't the unit for you. Go buy a real automotive wired gauge. If you want to know your cruising speed so as not to get a speeding tticket, this should do! One thing that may also effect accuracy is the proximity to windshield. You'll want a clear view to the sky/satellites! This is a great unit if your gauge went out and you don't feel like dumping hundreds of dollars into repairing the factory equipment (like me!) Next, it's USB powered, NOT rechargeable. Again, not a big deal. Just take a little time to route your cable nicely. The unit must have some type of memory as it remembers your settings when powered off/on. Settings seemed a little confusing, at first, but once you figure out it's super easy. All Settings with one nice button: HOLD button in to open each mode (1-8, think it was) then toggle button left or right to change setting. Pretty cool. Great selection of LED colors, too! I matched to the gauge cluster but many more.

Ok, not great. The horizontal segments aren't as bright as the vertical. Also the highest brightness setting wasn't all that bright.

Nice for old eyes! My speedo quit on my car so I threw this unit on the windshield until I can get the computer to talk to the dashboard again. Works great! May be showing a little fast compared to my good GPS, but that is fine.

I wish I could give it 5 stars but right now I can't . Up to about 50 mph, it is within 1 mph of the other 2 GPS read-outs in the car. However from 50 on up, it reads an average of 4 mph high compared to the other two. I don't know how to correct that. So, if your in something like a school zone, it is great. However on the road at cruise speed, it reads high. It's a problem I don't understand nor do I know how to fix it. I usually run about 3 mph over posted but if I depend on this, I am 7 over posted which puts me in the get a Ticket area. Anybody got any ideas?After a month of trying to figure out this thing and not having any success, I have turned it into a paper weight. Don't waste your money on this. The fault must be in the programming. It's not linear for sure.