Audio can be heard from the vehicle's speakers by connecting a commerciallyavailable portable audio unit to the auxiliary jack.
A commercially-available, non-impedance (3.5 ) stereo mini plug cable is required. Contact an Authorized Mazda Dealer for details.
In addition, audio can be played from the vehicle audio device by connecting a USB device to the USB port.
NOTE
The SD card slot is for the navigation system. For vehicles with the navigation system, the SD card (Mazda genuine) with stored map data is inserted into the SD card slot and used.

WARNING
Do not adjust the portable audio unit or a similar product while driving the vehicle:
Adjusting the portable audio unit or a similar product while driving the vehicle is dangerous as it could distract your attention from the vehicle operation which could lead to a serious accident. Always adjust the portable audio unit or a similar product while the vehicle is stopped.
CAUTION
Depending on the portable audio device, noise may occur when the device is connected to the vehicle accessory socket. (If noise occurs, do not use the accessory socket.)
NOTE
Seek Switch
How to connect USB port/Auxiliary jackMazda 6 Owners Manual: Accessory Sockets
Only use genuine Mazda accessories or the equivalent requiring no greater than
120 W (DC 12 V, 10 A).
Front
The ignition must be switched to ACC or ON.
Center
The accessory sockets can be used regardless of whether the ignition is on or
off.
CAUTION
To prevent accessory socket damag ...
Mazda 6 Owners Manual: Dehumidifying (With air conditioner)
Operate the air conditioner in cool or cold weather to help defog the windshield
and side windows.
1. Set the mode selector dial to the desired position.
2. Set the air intake selector to the outside air position (indicator light turns
off).
3. Set the temperature control dial to the desired ...