While it may not display as many parameters as other heads-up display units, the AceCar T800 displays the basics: speed, compass heading, and longitude and latitude.

Among the least expensive HUDs, it can perform acceleration and brake tests, but lacks basics like on-board diagnostic warnings and has only a six-month warranty. Overall, the T800 can provide insight into the automobile without distracting the driver.

This $46 heads-up display is one of the least expensive devices of its kind; AceCar makes several other automotive add-ons, including the $48 Tesla Model 3 HUD, which runs on Tesla's entry-level motor, and the slightly more expensive Model Y which is a $48 HUD

. At 2.2 inches tall, it only slightly obstructs the driver's forward vision. It also weighs 1.9 ounces, making it one of the lightest heads-up displays available.

The bottom of the T800 is flared to provide a secure base that can be attached to the dashboard using the included adhesive strips. A spare mounting strip is also included in case the car is replaced before replacing it with a new HUD.

Of note is the T800's 2.8-inch display, which is smaller than the PHUD180BD's 5.5-inch display. This display performs well enough in most situations and has a light sensor for automatic brightness adjustment.

Like the Sherox 3.5" HUD, the T800 has no on/off switch. There is a control wheel on the top of the HUD that switches between options each time it is pressed. There is a mini-USB port that connects to the car's cigarette lighter outlet for power. Unfortunately, the wire is round and thicker than other HUD cables, making it difficult to store in dashboard crevices.

Because it uses a GPS receiver, the AceCar T800 does not have access to the vehicle's OBD data, such as engine RPM. On the main screen, the vehicle speed is displayed numerically, with a curved bar below it. Dig a little deeper and you can see everything from the number of satellites in contact to accessory voltage and compass heading.

It can also display longitude and latitude for off-roaders, but it cannot show the car's location on a map or give directions; there is no OBD data, so it cannot diagnose problems either.

In addition to vehicle speed and direction, the T800 can warn drivers of excessive speed and low voltage. It can also test acceleration and braking for performance-conscious drivers.

The advantage of using a GPS signal for speed and location is that it will work in any car with a cigarette lighter outlet; plug the T800's power cord into the car's outlet and the system immediately started working.

Unlike many other HUDs, the T800 comes with only a six-month warranty. Furthermore, like the Sherox 3.5-inch HUD, the T800's documentation is sorely lacking: a four-page fold-out booklet covers very little of the basics, and the T800's software is not very well written.

Plugging the T800's power cable into the cigarette lighter outlet of a 2014 Audi A4 allroad, the screen activated. At less than two inches high, the T800 was one of the least obtrusive to the driver's field of vision - but its display was still viewable. It took time for the internal GPS electronics to boot up and connect with the orbiting satellites.

I really liked the fact that the T800's screen displayed speed in large white numbers with a bar graph below it showing speed. The speed was generally accurate, but as soon as I entered a tunnel, the speed was no longer displayed. The problem was due to the lack of connection to the GPS satellites mentioned above.

To change the display units, one must use the small control wheel on top, and the unit automatically shuts off when the car engine is turned off. However, I miss the on/off switch and the ability to leave it on for a few minutes (which the Pyle PHUD180BD has).

The acceleration and braking tests were good additions for anyone looking to get a little performance out of their vehicle. Unfortunately, however, the T800's GPS receiver misses the opportunity to deliver vehicle data and display current location on a digital map.

The AceCar T800 is the heads-up display to get if you don't need on-board diagnostic feedback; the GPS receiver can provide speed, longitude, and latitude data. However, some navigation support would be nice, even if it just shows the current location on a digital map.

Performance-minded drivers will be pleased with the ability to test the gas pedal and brake. That said, one can't help but wish the screen were a bit larger and the warranty a bit stronger.