Mazda 6 Service Manual: No.22 vibration concerns (engine)

No.21 engine noise

No.23 a/c does not work sufficiently

Other materials:

Mazda 6 Service Manual: Installation of radio system
If a radio system is installed improperly or if a high-powered type is used, the CIS and other systems may be affected. When the vehicle is to be equipped with a radio, observe the following precautions: Install the antenna at the farthest point from control modules. Install the antenna fe ...

Mazda 6 Service Manual: Vehicle speedometer sensor (vss) removal/installation
Caution Water or foreign objects entering the connector can cause a poor connection or corrosion. Be sure not to drop water or foreign objects on the connector when disconnecting it. If foreign materials are stuck to the VSS, disturbance by magnetic flux can cause sensor output to be ...