1. Place the mat to the front desk of the diver under the front windshield with adhesive surface. 2. Place the OBD HUD on the mat, adjust the view angle and position and make sure your vision clear. 3. Connect the OBD cable with vehicle OBD16 diagnostic port, if have any switch please turn it on. Then the indicator lamp lights up 4. Connect HUD 12 pin USB female port with the car cigarette power adapter USB male port 5. Start the car, then HUD power on, system will play the voice at the same time, monitoring data output