Source: Navdy.
Source: Navdy.
Source: Navdy.
Source: Navdy.
Source: Navdy.
Source: Navdy.
Source: Navdy.
Source: Navdy.
INTERNATIONAL - It was the last car on the rental lot: a white Nissan Altima that looked as if it had hit every pothole and puddle between Ohio, where it got its license plate, and Fort Lauderdale, where it was now parked.

I was at the beginning of a long weekend and had about 600 miles of driving ahead of me. This time, I vowed, I would give myself the kind of upgrade the rental agency wouldn’t—a heads-up display from Navdy, a $499 aftermarket gadget that sits on top of your dash and gives almost any car that Top Gun feeling.

My usual routine, whether driving my own car or in a rental, is to fire up Google Maps on my phone, stick it in the cup holder, and steal glances as necessary. The promise of heads-up display technology, on the other hand, is that it gives you the information you need as a driver—speed and navigation, primarily—without ever taking your eyes off the road. Using technology first applied in fighter jets, this is typically done by projecting the information onto your windshield in such a way that it appears to float in space, usually right around the the end of the hood of your car.

Source: Navdy.
Those displays are floating above many hoods these days. The 2018 Lincoln Navigator, which uses a “digital light projection” technology frequently used in movie theaters, creates what they say is the largest, brightest automotive display in its category. Because your line of sight needs to be just so to see the HUD, some luxury cars like Mercedes and Volvos will save the position of the display to match your seat settings. Not all car makers have embraced the technology, however. Drive a Porsche or a Tesla, or an old Audi, for example, and you are out of luck.

Enter Navdy. It’s the leader in a growing field that ranges from budget apps, which reflect your phone’s screen onto your windshield, to Garmin’s $179 HUD+. The Navdy consists of an adhesive base, which sticks to the dashboard; the display unit, which connects to the base magnetically; and a scrolling thumb controller that straps onto the steering wheel.

The Navdy projects its information onto a clear lens, about 6 inches wide and 2 inches high. (Mazda also uses this lens-based approach). The effect, ultimately, is the same as a HUD that’s embedded in your dash, even if the implementation is a little unwieldy.

Source: Navdy.
It gets its information from two sources: your phone, which connects via Bluetooth and its app, and the car’s on-board diagnostic, or OBD-II port, through which the Navdy collects such performance data about your vehicle as speed, engine temperature, and fuel consumption. The OBD-II port also provides power to the Navdy, which means that it works only in cars made after 1996, when the port became standard. It also means a cable runs from the base to the OBD-II port, usually located beneath the base of your steering wheel, or near the fuse panel. Cable stays keep the whole affair tidy, but there’s no way to hide the wires entirely.

Installation takes about 15 minutes, but getting used to the display takes a little longer. The default mode shows speed and RPM in the center, with additional information—time, g-force, engine temperature, and compass heading—in flanking displays you can scroll through as needed. Alerts for lurking speed cameras, or subtle notifications for the vanishingly rare moments I exceeded the speed limit, made themselves known without being distracting. When in GPS mode, the bulk of the display is filled with a turn-by-turn map display. Destinations are entered by voice—just hold down the button on the thumb wheel and say where you want to go.

Beyond the purely functional aspects of driving, Navdy serves as something of a media and communications hub. Alongside your speed or navigation information, emails and text messages can pop up in “Glances,” should you choose to have them do so. There’s an option to have them read aloud, as well. You can also engage or dismiss these messages with a wave of your hand, though I found that the thumb wheel was a more natural, less distracting way of dealing with them. Replies are canned (“I’m driving with Navdy. Call me”) but customizable.

Source: Navdy.
For the first few hours, particularly while I was noodling around with it to set up Spotify over the car’s speakers, I found it could be just as diverting as anything on my dashboard. After a while, it became a part of the landscape, like any other road sign or traffic signal. It was only when I returned to my own car, with my cup-holder GPS method, that I realized the extent to which my eyes were taken from the road by that arrangement.

But I left it thinking that this is the way we’ll all be driving in the future. Like the transition to electric—or autonomous—vehicles, HUDs seem to be a logical, inevitable next step. Car manufacturers seem to think so too: Groupe Renault just announced that it’s making the Navdy an option with its cars throughout Europe in 2018.

- BLOOMBERG