Getting a BMW Spare Key The BMW's key fob might need an upgrade in battery. Or perhaps you want to upgrade to a smart key, which substitutes your compatible smartphone as a key. BMW must prepare replacement fobs for your car using its VIN. This is done to ensure security. https://carkeyreplacement15401.blogtov.com/10631138/what-is-bmw-key-1-series-and-how-to-use-it