If you want to save $350 or more, you can also carefully remove the sensor, drill out a 1/16 through hole at the center of the rotary arm & stationary portion...then screw the rotary arm back in place with a tiny screw. I just finished this on mine & it works great. **Just make sure you have a low profile screw head so it doesn't bind into the silver sway arm. Also, you want to wallow out the rotary arm hole a little bigger than the screw - that way the screw only holds into the stationary sensor portion. You don't want the rotary arm engaged w/ the screw trying to turn it.
I kept bumping the "trunk close" button when trying to pull away the trunk lid trim. If you remove the 2 top right fuses 10A & 5A in the left trunk fuse block, the trunk lights & trunk operation will stop while you work on the sensor.