I researched the tuner I need and purchased it but I'm not sure where to install it. I've read both "passenger kick panel" and rear hatch; neither looks very obvious to me. There was a video link floating around but it seems to be broken. Not sure which panel needs to be removed, how to remove it, etc...any advice?

 

I got the plastic door open in the rear and I see the cables; does the tuner go under the panel or get mounted outside? Seems stupid to have it on the outside but I don't know how to get it underneath