Factory firewall hole for engine computer connections
This is the area behind the glovebox, which doesn't have to be removed.
The hole is tricky to see, if not nearly imposible, but just fish wire from the engine side into the car at a downward angle, eventually it will be on the passanger floor. Best way: Have a friend look for the wire as you fish it though the hole.
Just go with the flow!
Run the wires either though the oem tube or tapethem/tie them to it.
Junction before the back seat
Fishing behind the rear seat, you're able to pull it from the side enough to slip a stiff wire and use that to pull your wires.
In the trunk compartment, carpeting pulled