What an excellent idea. No more twisting awkwardly to get in or out of the car. A low profile swivel cushion which glides smoothly will help. So comfortable, with memory foam, you will never know it's there, until it's time to get out the car.
The cushion has a fabric tag to slide down between the seat and the seat back, to secure the bottom layer of the cushion, and once safely in the car, there is also a loop to feed the seat belt buckle through, to prevent the top layer of the cushion from rotating once you are on your way.
Can also be used on stools, dining chairs etc. as it has a non-slip base.