Pulling trim and running wires

I've got a 2012 Prius with moonroof and nav, and I want to install front and rear dashcams in case of accident or vandalism. I'm trying to figure out how to run invisible wiring. I'm new at this, so I could use some advice on pulling trim. I haven't been having much luck. Maybe I'm being too cautious with it, but I'm afraid of cracking plastic. Are moulding removal tools essential?

If trim removal was not scary to me, the front camera looks relatively easy. I could run the wire up the EC mirror conduit and hook up to the map light. The conduit comes off easily, but not the roof top moulding. I found this document which shows diagrams for other Gen III models, though not quite mine:
http://priuschat.com/attachments/p3_interior-panels_removal-pdf.18985/
I do not have LKA, so my version would be the "w/ EC Mirror" which is not shown.

Perhaps a simpler alternative for the front camera is to just stuff the wire into the headlining. I can get all the way down to speaker this way, but then what. I found this other document, but again they just seem to say that these parts come off with a moulding removal tool:
http://priuschat.com/attachments/dash-dis-prius_tns510_lhd_pz445_00333_00_aim_001_664_1-pdf.19030/

The rear camera is harder. The plate lights turn off when the headlights are off, and the GPS display dims when the headlights are on, so that's not a solution. I'm tempted to cannibalize the rear wiper, but I'm thinking that I'll need it in the Canadian snow. Might there be a way to replace the rear wiper intermittent function with my camera? I'm guessing not, which means running the wire into the body of the car.

I could go through the rubber conduit that already links the door, but then that means pulling the headliner, which seems like a big and risky job. I can't even seem to pull out those three button clamps just in front of the hatch - do they come fully out of the headliner, or are they retained by it? As an alternative I could drill a small hole on one side and just deal with side trim, and maybe find cracks to just stuff my cable going forward. But then I would have a long meandering path to go before I reach the cigarette lighter. And what's the best way to seal my hole to keep the rain out?