Universal Vortex Generator. You will need 10 or 12 pieces to cover the backside of the roof of the car (sedan).
Meant to improve airflow to reduce drag,thus saving fuel at higway speeds.
Use double sided tape to fix teh VGs to the car.
Yaw angle 15 degrees near the car centre line of the car (in the front to back directions) to 0 degrees at outer sides (left and right). Gradually decline from 15 to 0 degrees for the VGs in between mid and outer VG's.
Can be painted. Follow guidelines of paint supplier.