Sat-nav makers Garmin have created a gadget that projects directions and navigational information on to a vehicle's windscreen.

The portable HUD (head-up display) works with a smartphone and displays information from navigation apps on a transparent film mounted on the windshield.

The result is very 'Airwolf' - but it's about more than looking good.

By providing comprehensive road guidance at a glance and right within the driver’s line of sight, HUD can help increase safety and reduce driver distraction.

“HUD redefines the navigation experience by allowing drivers to find their way without taking their eyes off the road,” said Dan Bartel of Garmin.

“Head-up displays currently have their place in select high-end cars, but HUD makes this technology available as an aftermarket accessory for any vehicle, at an affordable price.”

Complementing the visual display, spoken turn-by-turn directions are provided simultaneously by a compatible Garmin or Navigon app1, either through the smartphone speaker or a Bluetooth-connected car stereo.

Music streamed to the car stereo from the smartphone will automatically fade out for turn-by-turn voice prompts.

The HUD is expected to cost about £86 on launch in late summer. Regional maps for the associated Garmin app will cost about £20 each.