Maybe a little late here, but there’s a grommet that’s just under the brake master cylinder. It comes into the cabin just above and behind the ebrake pedal. Just had to jab a knife through it to make a hole for 8-10 gauge wire and fish it through.
I’ve read the hole in the firewall is meant for a manual trans clutch pedal that isn’t used in these cars so it’s just plugged up and empty.
I ran my power wire across the top of the firewall then down into that grommet, straight back along the bottom carpet trim into the trunk.
