Yep, im a big dumb dumb and was trying to get the wrong thing off for the plastic. I did end up removing the entire spoiler which was 2 more screws and 2 clips and was able to get everything installed. I ended up installing the camera more towards the middle than you have you have yours but will have to remount because again... dumb dumb... Did not account for the window while I was installing the camera so it buts up a little too close to it. Ah, the joys of DIY.The black plastic piece just under the rear wiper pops right off. Start by pulling down (gently) with the lift gate closed, the right side of the piece just under the wiper motor.
For the spoiler, after you remove the 4 bolts located under the black rubber grommets, it give it enough opening to run the cable through. You don't have to remove it in order to run the cabling.