Purchase a car camera mount. High quality camera mounts can be purchased inexpensively at a website called Film Tools. Manfrodo brand mounts can be purchased for less than $100.
Attach the camera to the camera mount. Locate the tripod socket on the bottom of the camera (the place where the tripod screws into). Screw the camera mount into the camera's tripod socket. Ensure that it is screwed in tightly.
Attach the mount to the car. Most camera mounts use a suction cup to attach to the car's body or window. Locate a flat surface on the car to attach the camera mount to. Push down on the suction cup of the mount on the car body. Most mounts also have a side pump located next to the suction cup to pump out any excess air ensuring a tight seal. Pump out any excess air.
Adjust the camera mount so that the camera is pointing in the direction of the desired shot. Tight any screws to lock the position of the mount. Press record and start driving to test the mount. Most professional mounts are secure at speeds over 150 miles per hour with a standard sized video camera. Check the instruction manual for additional details on how to operate.
To remove the mount simply peel the suction cup off at one of the sides.