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: Cruise Control (Some models)
With cruise control, you can set and automatically maintain any speed of more
than about 25 km/h (16 mph).
WARNING
Do not use the cruise control under the following conditions: Using
the cruise control under the following conditions is dangerous and could result
in loss of vehicle control.
...
Mazda 6 Owners Manual: Recommendations for Shifting
Upshifting
For normal acceleration, Mazda recommends these shift points:
For cruising, Mazda recommends these shift points:
Downshifting
When you must slow down in heavy traffic or on a steep upgrade,
downshift before the engine starts to overwork. This reduces the chance of stalling
and ...