Abrown3mtg

I have a 2010 E550 4matic so unfortunately my battery is under the hood vs in the cargo bay. I am wiring a subwoofer into the car right now and curious is there is a good place to run a 4 gauge/awg wire from the cabin through the firewall and to the battery. I would kill for there to have been a good point to tap power at the rear! Amp is a 500/1vs JL pushing a 12w6 (fuse block wiring I've seen people try here isn't an option).

Thanks in advance

SOLUTION: Remove batter from vehicle…. there is one small rubber grommet behind it. remove and pass the wire through….. trim grommet and reinstall over the wire….