How to run XM Antenna & Backup Camera Pinout on a 2013 Persona?

I've been doing quite a bit of searching on the forum and can't seem to find the specific scenario I'm in, I've seen a lot of posts on running XM antenna wires to the stock XM unit under the passenger seat but in my case I want to place the antenna on the roof, run it through the hatch and run it to my new aftermarket head unit. What is the best way to do this and hide the wires? Is there a post anywhere that shows the best way to remove the trim and get the wire behind the dash? It looks like I should be able to stuff it behind the trim on the ceiling and go down the pillar on the passenger side but I'm not quite sure how to get the wire to the HU, it looks pretty blocked off.

Also, I want to connect my factory backup camera to my new HU.. Is there a pinout anywhere which shows where I can tap into on the factory harness? I'm assuming all I need to tap into is the two video leads and the backup lead.. I'm hoping the camera is still getting power without the stock HU.. anyone know?

I'm going to be adventurous and attempt to do this during my lunch break today.

Thanks,

-Keith