Can someone describe the location?
On both sides if possible (engine bay and inside as well).

 

It's up and to the left of the brake pedal. If you get a flashlight you can see it. You don't have to remove the panel underneath the driver dash to get see, but if you want to run a wire through it, it will be a lot easier to access if you remove that panel. There's a black rubber boot that covers it.

It comes out the other side in the engine bay on the driver side. I don't think you can see the hole very well if you are looking from the engine bay, but if you reach underneath and around the factory strut tie bar, you should be able to access the whole or at the very least pull a wire if you fish it through from inside the car.

 

FYI, on the 06 I couldn't find the hole at all. I looked where people said it was on the 04/05, but to run my stereo I ended up drilling a new hole, running wires, and filling it with hot glue.

Not saying its not there, but I never found it after poking around for longer than necessary.

 

I poked a hole with a hanger from the engine bay and felt for it behind the radio, I would suggest doing that, and pulling your wires back through with the hanger