The OBD interface in a car is normally located below the controls, however, that fluctuates from manufacturer to manufacturer. In older cars, the port can be from the back or close to the hand brake. Once you have located the access interface, you can readily plug in the reader in and the connection between your car and the vehicle diagnostic apparatus will be established. https://www.globenewswire.com/news-release/2020/12/31/2152200/0/en/fixd-sensor-reviews-best-odb-ii-car-sensor-product-review-by-rick-finn.html