Heads up!

Transparency doesn't only LOOK good, in some situations it could actually save lives. When driving, looking away even for a fraction of a second could be dangerous, and so this Heads-Up-Display by Pioneer is both cool and safe.

 

http://www.pioneer.eu/eur/newsroom/news/hud/page.html?

The pioneer is a tad pricey at around $1000, but Garmin's solution might be a more economic option:

For $150, this unit connects to your phone via BlueTooth, and talks to Garmin's navigation software. Then, it beams the data onto a special transparent film that you place on your windshield.