BMW AG of Munich is developing a multifunction car key that will include contactless payments capabilities.

The automaker said that its BMW Group Research and Technology unit is working with the Dutch chip company NXP Semiconductors, and that they plan to demonstrate the device next month at the Cartes & Identification trade show in Paris.

BMW said it is considering several features beyond adding a standard credit card account for purchases at the point of sale, including storing prepaid funds for public transit, or temporarily connecting the key, and the payment account, to other vehicles, such as rental cars.

"With the concept of integrating contactless payment functionality in a car key, we are working on the combination of automotive technology and lifestyle," Raymond Freymann, the managing director of BMW Group Research and Technology, said in a press release Tuesday. "In cooperation with NXP, we are doing research in enhancing the capabilities of the car key into one smart device for access, payment, and services that will simplify the lives of BMW car drivers in the future."