Using technology that already exists, Samsung has shown off a Smart Windshield intended for motorcycles. The system uses a smartphone and a small projector to place important information on your windshield, such as phone call and navigation info. Since so much info can be displayed, there are concerns that a system like this would be a big distraction.
Samsung hasn't put the Smart Windshield into production, but the components required for it are available or could be made.
A video from the company shows how the product would operate by syncing with your phone.