Everyone wants to know what Google Glass is good for. I've figured it out: It's the killer app for your car.

I spent several minutes playing with a prototype pair of Google Glass, and while the phone and messaging notifications are cool and the interface is surprisingly slick, it's the navigation and GPS functionality that has me champing at the bit.

For the moment, forget the knee-jerk potential for distraction. Legislators are already drafting laws against using wearables in the car. But think about it. What's more dangerous behind the wheel? Constantly checking and poking a small smartphone screen stuck to your dash or tucked away in a cup-holder, or simply glancing up – through a transparent screen directly in your field of view – to see when to make your next turn.

Even built-in systems designed by automakers aren't much better, with small touch points, horrid user interfaces and finicky voice controls.

Now I'm not talking about text messages and Tweets – this is the ultimate head-up display for your car. Glass could replace everything from speedometers to music controls. And do it better in the process.

It doesn't matter if you're in a clapped out Corolla or a $250,000 Bentley, you get the same experience. And since it's not hard-wired into a vehicle that was developed four or five years ago, it has the potential to surpass the systems fitted to high-end machines from Audi, BMW and Mercedes-Benz that were outdated the moment they landed on showroom floors.

With Google Glass in-car obsolescence is now obsolete.

Map and software updates are constant. Google is always rolling out improvements to its routing and location data. Throw in real-time point-of-interest search – something that automakers are just beginning to get a handle on – and you've got a seamless connection to the best navigation and destination data available. Did an accident just happen up ahead? Automatic re-routing is a simple voice command away.

With Google Glass Explorer editions shipping to developers now, the potential for auto-related applications are unlimited.

Let's start with the on-board diagnostics (OBDII) port underneath your dash. That plug – standard on all cars since 1996 – allows your mechanic to check diagnostic information, clear fault codes and figure out why your ride is making that awful clanking noise. But it also supplies a host of data that companies like Automatic are tapping into.

Google Glass could be paired over Bluetooth to a dongle plugged into the OBD port, providing not just vehicle speed and engine revs, but everything from coolant temperatures to fuel level. Sure, that's likely baked into your instrument panel already, but what if you want to quantify your driving habits? Figure out what's the most fuel-efficient route to work? What if Glass could tell that your heavy acceleration and hard braking is killing your fuel economy? It can. It will. All in real-time.

What about the weekend racer crowd? Nearly every speed junkie mounts a GoPro in their car to record their track-day antics. Leave that at home, slap on Glass and record video of your high-speed hijinks, with G-forces and cornering data overlaid on the display. Then upload it to YouTube when you're back in the pits.

And what about the safety? Glass has a built-in accelerometer that allows you to tilt your head up or down to scroll through menus and lists. What if that same accelerometer was used to detect a drowsy driver? Ford is doing it with steering inputs and Mercedes is working on eye-tracking technology. But with something mounted directly to your head, if you nod-off behind the wheel, Glass could react in milliseconds to sound an alarm through the built-in speaker.

Google Glass has the potential to do for wearable technology what the iPhone did for mobile computing. It just needs the same smart, innovative developers to tap its potential. And when it comes to the automotive world, the possibilities for improving both safety and convenience are just waiting for the right developers with the right imagination to make it happen.

Devs: Get to work.