Bottle holders are on the inside of the doors.

CAUTION
Do not use the bottle holders for containers without caps. The contents may spill when the door is opened or closed.
Cup Holder
Storage CompartmentsMazda 6 Owners Manual: Recommendations for Shifting
Upshifting
For normal acceleration and cruising, Mazda recommends these shift points:
*1 Always observe local speed limit regulations.
Downshifting
When you must slow down in heavy traffic or on a steep upgrade, downshift before
the engine starts to overwork. This gives better acceleration w ...
Mazda 6 Owners Manual: Locking, Unlocking the Doors
NOTE
The system may not operate if you are too close to the windows or door
handles.
If the key is left in the following areas and you leave the vehicle,
the doors may be locked depending on the radio wave conditions even if the key
is left in the vehicle.
Around the dashboard
...