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: Rocking the Vehicle
WARNING
Do not spin the wheels at more than 56 km/h (35 mph), and do not allow
anyone to stand behind a wheel when pushing the vehicle: When the vehicle
is stuck, spinning the wheels at high speed is dangerous. The spinning tire could
overheat and explode. This could cause serious injuries.
...
Mazda 6 Service Manual: Seat Warmer (Some models)
The front seats are electrically heated. The ignition must be switched ON.
Press the seat warmer switch while the ignition is switched ON to operate the
seat warmer. The indicator lights turn on to indicate that the seat warmer is operating.
The mode changes as follows each time the seat warmer ...