1. Verify that the joint shaft is not twisted or cracked.
2. Turn the joint shaft by hand and verify that the bearing rotates smoothly and freely.

Drive shaft
Joint shaft removal/installationMazda 6 Service Manual: Moonroof (Some models)
The moonroof can be opened or closed electrically only when the ignition is switched
ON.
WARNING
Do not let passengers stand up or extend part of the body through the open
moonroof while the vehicle is moving: Extending the head, arms, or other parts
of the body through the moonroof is dan ...
Mazda 6 Service Manual: Plastic Part Maintenance
When cleaning the plastic lenses of the lights, do not use gasoline, kerosene,
rectified spirit, paint, thinner, highly acidic detergents, or strongly alkaline
detergents. Otherwise, these chemical agents can discolor or damage the surfaces
resulting in a significant loss in functionalit ...