To install a backup camera, install the camera to the license plate bracket using the kit provided. Run the wire from the camera through the hole that goes to the license plate light, if possible. Drill a small hole in the hatch or trunk if necessary for wire access.
Splice the wiring that feeds the backup light so that it connects to the backup camera. This circuit only draws power when the car is in reverse, but that's the only time when the camera is necessary. These cameras transmit video wirelessly, making a wire through the cabin unnecessary.
Mount the integrated mirror/camera over the existing mirror, using the clamps to connect the new mirror to the top and bottom of the factory mirror. Attach the Velcro straps to keep the new mirror in place. It's possible to run the power cord straight down to the dashboard power outlet, but another way is to tuck the cord into the front of the headliner, routing the wire down the A-pillar on the drivers' side. From there, conceal the wire behind the trim and lead it into the dash.
In some cars, a trim removal tool or screwdriver is necessary to remove the A-pillar. Connect the wire to the fuse box, or plug it into the console power outlet after running it through the dash.