The reading on this is always about 5mph more than my speedometer reads. Also, without another set of hands I don't know how you could ever put the reflective sticker on the windshield. If I lean forward to place it on the windshield then I can't see where I need to put it. All in all it's nice, but could be better. The power port for the unit is on the front of it, even though they know you're going to have to run the cord back towards to the dash to plug it in. Why not put the power port on the back of the unit??

The HUD looks great displayed on the windshield. Unfortunately, the speed is off by 3 to 5 mph with no way to calibrate.The M1 allows for calibration.

It's at least 5mph off. Trash.

I like that it's small and fits anywhere on the dash. The power cord is long enough to tuck away and not be seen. The display is bright enough to be seen, with or without the reflective piece, although it does fade some in really bright light. I have it mounted right in front of my steering wheel, reflecting lower on the windshield and it's not distracting at all. My only concern is how is it going to handle the extreme heat on a vehicle dash in the summertime? Guess we'll have to wait and see, but for now, it's awesome.

I love having my speed in my line of sight. The kit includes a clear film that is applied to the windshield to reflect the display. Polarized sunglass do reduce the visibility of the readout.

This is luckily a common sense install if you’ve ever installed anything on your dash. It really comes down to what will be out of the way of most of your road view and not be a distraction. I wanted to place this closer to the dash over the instrument cluster but that was going to place the numbers reflection directly at eye level to the road. I chose to place it in the bottom center of the windscreen to avoid visibility issues and so it would have enough view of the sky for the gps sat to monitor speed. You will know when it connects because once you plug it in it will show a zero speed instead of the dash across the screen. On my Verano the digital screen monitors way too much and speed isn’t always up. I’m so used to that being front and center that I don’t always look at the correct dial for my speedometer and sometimes find myself looking at the tachometer. Where I have it is tucked away behind my CarPlay unit and the photo I took is in a parking lot with the camera viewing from where my head is at, at eye level. After installing the reflective film, which practicing placing that to see where the best view would be took most of the time placing this. The true test will come in the summer to see if the sun am doesn’t actually bake this off the dash given how much sun the giant windshield lets in even with a solar reflector up.

- Inaccurate Speed -It's important to note that the Global Positioning System (GPS) does not provide speed data to a device. Any GPS receiver (this product, your smartphone, etc.) must calculate the speed on its own, and there are a multitude of ways to do this. The most common method is to keep track of the distance traveled and then divide that distance by the time between location updates (distance / time = speed).I checked this device's shown speed against the speed shown on my Samsung smartphone. I checked the speed shown both from a popular GPS data app (GPS Status by Propane Apps) and from Waze, a navigation app with an included speedometer. Both of these apps consistently showed the same speed. These speeds were matched to my vehicle's speedometer and no discrepancies were found.This product always showed a speed higher than my actual speed. The increase in the indicated speed grew as I traveled faster. At 20 MPH true, it was indicating 21-22 MPH. At 40 MPH true, it was indicating 43-44 MPH. At 60 MPH true, it was indicating 65 MPH. This effectively renders the product completely useless as its indicated speed has such a high margin of error. That being said, I took several trips with this product and the speed difference was always consistent. While this obviously is not good and indicative of a poor product, that does mean you can reliably know your true speed if you subtract the correct amount from the speed shown on the HUD. In my opinion, however, this is unacceptable.- Misleading Description -In order for this product to work effectively, you need to place a semi-transparent, reflective pad on your windshield. This will noticeably increase the visibility of the HUD but will also obstruct your view outside of your windshield wherever you place this pad. I opted not to use this pad and instead relied on my windshield alone to reflect the HUD. For me, this was actually sufficient as the device can get rather bright. I did not have an issue seeing the speed during the day. That being said, it is still very dim in such conditions and I am young and have perfect vision. Not everyone would find this to be a pleasant or usable experience and would have to use the reflective pad.The description does not mention the need for this reflective pad. Its only mention is in one of the seven product images where it is labeled as "reflective film" and is shown along the other contents of the product's package. The manufacturer/seller is purposefully avoiding pointing out this film as to give the illusion that it can be used as a "true" HUD for your windshield. As I said, it can be done, but the results are not good. I was aware of the included film and expected the results I got, as well as the need to use the film for the best visibility of the HUD, but I wanted to test out the product anyways so as to give this feedback. If it weren't for giving this review, I would not have ordered this product.- High-Pitched Whine -The internal electronics of this product produce a rather annoying high-pitched whine. The intensity of this while decreases with a decrease in the display's brightness. This leads me to believe that the whine is coming from a small internal power supply responsible for lighting of the seven-segment displays as well as dimming the brightness based off the photo-resister. The noise becomes less apparent while driving thanks to your vehicle's engine and general road noise, but it is very noticeable when parked and with the engine off. While this isn't necessarily that important of a criticism, I would argue that it is a sign of poor build quality. Combined with the other two large issues I've addressed, it's the cherry on top.

This seems to work fairly consistently throughout the normal driving range. It is a few miles per hour higher than my vehicle's speedometer. I would say that it could be the speedometer, but my speedometer is on par with the GPS in my Uniden R8. To me this doesn't make a lot of sense since the device is GPS driven, but it does seem to get a little closer as I drive a little longer.Other than that, the digits are easy to read in the windshield and it is nice to have this feature in an older vehicle. I do like the device and won't pull it because of the slight MPH discrepancy. I need to drive a little slower anyways.