This is the best method i have found to pass a power cable through the firewall for a sub install. This was done on a 2012 Maxima S.

1. Remove the glovebox. There are 8 black screws holding it in. 3 on top, 3 on bottom, and 2 inside of the glovebox.
2. On the right side near the white box with some wire bundles, slide away some of the insulation and you will find a rubber plug. Remove the plug and you will feel a slight breeze and see some light shine through. You are now through the firewall!




3. Drill a hole in the rubber plug and pass the power wire through



4. Pass the power wire through the hole until you have enough wire in the engine bay and then put the rubber plug back in the hole



5. The wire comes out near the passenger side of the engine bay, run it to the battery and secure with zip-ties and electrical tape.



6. Put back glovebox and DONE!

 

Nicely done!

It's easier than drilling through metal & safer than going through the grommet with the wire bundle on the driver's side.

 

Thanks! yea, that was one of the main reasons i was so hesitant about putting in a sub because i didn't want to mess up drilling or accidentally cutting a wire. I can finally replace my small under the seat sub with a real one in the trunk. I just hope the new sub doesn't sound too muffled being that its in the trunk and isolated away from the passenger compartment.

 

Yup, I ran 1/0 gauge through that grommet on the drivers side, it was a tight fit, but through some light hulking out I was able to pull it through and have it come in to the car facing down, didn't even have to cut it.