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: Instrument cluster repair
Note
The needle of speedometer or tachometer may continue to rotate
clockwise until it indicates over maximum graduation. If a customer
complains of this concern, repair the needle position according to the
following steps.
1. Verify the concern.
2. Turn the ignition switch to LOC ...
Mazda 6 Owners Manual: Liftgate adjustment
1. Measure the gap and height between the liftgate and the body.
2. If not as specified, loosen the liftgate hinge installation bolts or the
liftgate striker installation screws, and reposition the liftgate.
Clearance
a: 3.0-7.0 mm {0.12-0.28 in}
b: -1.0-3.4 mm {-0.04-013 in}
c: 2.8-5.2 mm ...