This is what I did on my 11: look @ that A/C line straight @ the firewall as it dips down look straight back & down to the left.
There should be a big rubber plug & big wire harness thru it...it is the main harness that goes to the passenger foot-well fuse panel
It is a bitch to get it thru there but it can be done....
I got thru the first rubber layer kinda easy....it is the 2nd rubber layer on the inside that is the problem !!
I used a extended length 5/8 drill bit...
That rubber is real soft & I had trouble getting it to bite into that 2nd layer....when it did break thru It was REAL sudden...
I guess the drill bite nicked 1 of the headlight wires & cut it on the inside ....So be careful !!
There is actually lots of room there but it's still a pita to cut thru !! Good Luck

 

If you have more than just that heavy amp cable, or feeling adventurous, you can disassemble the firewall harness boot and route your wire(s) the OEM way:



Gotta unplug all the connectors up in the passenger's side dash in order to pull out the boot far enough, then it's just a matter of untaping the boot and harness, inside and out:





Stuff your wires through the boot:




Then start retaping every thing:





Easy as cake, right?

 

Same here. You have to push the insulation in on the other side of the firewall.

 

With due diligence and breathing practices, I got the wire thru the firewall without damaging anything. The rubber grommet on pass side was the way to go. Just have to find the happy angle and it'll work out. Thanks all.

 

if power wire were 14g that would work but nothing bigger than that is going to fit according to the reviews, so it is pointless for running power/ground wires.

 

agreed.