This product is excellent and of high quality. It functions very well on a Golf 7 using the OBD port. During setup, the device initially showed a 3 km/h discrepancy compared to the car's speedometer, but this was easily corrected by adjusting the menu option 1 setting to 104 (-3 km/h difference),and it then worked perfectly. No windshield sticker was necessary, as the device looks good on its own. The display is easily visible both during the day and at night. Thank you!