Guide lines which indicate the width of the vehicle (yellow) are displayed on the screen as a reference to the approximate width of the vehicle in comparison to the width of the parking space you are about to back into.
Use this display view for parking your vehicle in a parking space or garage.

a) Vehicle width guide lines (yellow)
These guide lines serve as a reference to the approximate width of the vehicle.
b) Distance guide lines.
These guide lines indicate the approximate distance to a point measured from the vehicle's rear (from the end of the bumper).
CAUTION
The guide lines on the screen are fixed lines. They are not synced to the driver's turning of the steering wheel. Always be careful and check the area to the vehicle's rear and the surrounding area directly with your eyes while backing up.
Displayable Range on the Screen
Rear View Monitor OperationMazda 6 Owners Manual: Ignition switch inspection
1. Disconnect the negative battery cable.
2. Remove the column cover. (See COLUMN COVER REMOVAL/INSTALLATION)
3. Disconnect the ignition switch connectors.
4. Inspect for continuity between the ignition switch terminals using an
ohmmeter.
If not as specified, replace the ignition switch.
...
Mazda 6 Owners Manual: Curtain air bag module removal/installation
Warning
Handling the air bag module improperly can accidentally deploy the air bag
module, which may seriously injure you. Read AIR BAG SYSTEM SERVICE WARNINGS
before handling the air bag module. (See SERVICE WARNINGS.)
1. Turn the ignition switch to LOCK position.
2. Disconnect the nega ...