I just ordered a 2 channel dash cam and now I need to figure out how to wire it up. I know some of y'all have them and I'm curious how you got it installed.

The biggest challenge I think is how do you get the wiring to the rear camera?

Remove the headliner?
Run the cable underneath the car?
Tuck it into the edge of the headliner?

I talked to the install guy at Best Buy and he wasn't much help.

For that matter, how does the wiring go into the front camera? The idea of a loose wire dangling from a lighter up to the camera is a non-starter for me.

I've been in a couple of rear end collisions (one minor, one pretty rough), so IMO having the rear camera is every bit as important as the front facing one.

For my front camera I ran the wiring along the headliner (stuffed it in the edge), stuffed it in the passenger side A pillar crease, beside the glove box, up under the glove box and round to the cigarette lighter. When I swap out cameras to get front and rear, I'll probably tap into the mirror power to power the cameras and run the rear camera wiring through the headliner.

for the front go up the a-pillar and along the headliner, to get to the rear i'd go under the door sills to the back then up the back pillar

The biggest challenge isn't running the wire to the rear, it's mounting the rear-facing camera

This thread has some good info on how to mount the cameras.

Rear facing dash camera ideas?

You can run your cable for the rear camera along the inside of your door seals and tucked into the plastic valances on the B pillars, C pillars and the plastic headliner trim over the rear cargo area. Pop the cover off the top bolt for the A-pillar hand grip and loosen it enough to make a nice gap to easily tuck your cable then re-tighten and recap. The rest is simple, as if that just wasn't. Finally under the rear hatch seal. Used a small piece of plastic dremel'ed out of an old Apple ear bud package and used it to do the headliner button mod to mount the rear cam. You don't need a huge slab of plastic back there, the rear cameras from pretty much all manufacturers are very light.