I just needed like 6 more inches. So close. I didn't have enough to tuck the cable under the molding on the C pillar. But even if I had 6 extra inches I probably would still do it over again with the longer cable to run it under the floor trim because the B pillar molding with the airbag is too tight to hide the cable around its edge, and it would bug me seeing the wire wrapped around the top edge of the B pillar. I don't want to mess pulling off the trim on the B pillar since the airbag is behind it. Running a long cable along floor should be quick and easy.
I popped off the rear upper brake light cover to hide most of the cam cable under it. If anyone plans to do the same on BMW, pull down on the cover from the side closest to the glass. There are clips on the side closest to the front of the car that will probably break if you pull down on them. You need to pull down on the back to pop out the two vertically mounted clips about an inch down, and then slide the cover towards the rear glass to pull the other two front clips out that are mounted horizontally.