Abstract: A drive system is provided for moving a lockable vehicle part. The drive system includes a drive element that operates with a change in length. The element is supported at its ends on the vehicle part and on the body. A releasable snap lock is provided by which the vehicle part is locked in one of its end positions. The snap lock is released by a control stroke of the drive element effectively connected with the release mechanism of the snap lock. The control stroke precedes the working stroke to move the vehicle part by connecting one end of the drive element to a release mechanism. In order to reduce the space required in the vehicle for the drive system, a rotary joint is provided as the release mechanism for the control stroke of the drive element.