Firewall *********** for Inverter Installation

[geopunk]

I am trying to install a 1500W inverter in my 2011 Yukon XL. I found a nice place between the glove box and the firewall, which is perfect because the battery is really close. Thing is, I need to find a way through the firewall so I can connect the inverter cables to the battery. Can someone please give me some advice on where to find a pre-existing *********** or where to drill a new one? Many thanks....

 

[ovasquez]

I drilled through the firewall right below the glovebox. I think that there might be pre-existing hole under the passenger seat.