In-vehicle ignition keys

Today, several proprietary radios enable key and less entry and proximity sensor capabilities to unlock car doors or start the ignition. But because these links are not based on standards, each accessory must be compatible with the specific proprietary technology or it will not work. Wireless in-vehicle that include Bluetooth Low Energy (LE) capabilities, however, enable interoperability with all in-vehicle wireless systems, allowing consumers to use any of their mobile accessories to open car doors or start the ignition. The advent of the Bluetooth LE specification represents a paradigm shift in efficiency, enabling dramatically increased battery life for Bluetooth products.

refer to: http://embedded-computing.com/articles/wireless-accelerate-next-wave-in-vehicle-innovation/