Why do you need a windshield display for your car? The windshield or head up display keep your head up while reading information about your speed, rpm, battery voltage and more. Its an accessory that is connected to the OBD2 connector. Data Link Connector is located near the steering wheel under the dashboard just above thee brake pedal.
It display digital information about speed in kilometers, Battery voltage, Revolution per minute, Coolant temperature and the ability to configure various alarms like over speed alarm including coffee break alarm after 4 hours since engine started.