Hi guys, I'm trying to install a subwoofer but cannot find the firewall between the battery under the hood to inside the car to install the power cable.

Does anyone know if there is another battery at the back to which I can tap into or any way to get through to the battery under the hood.

Or any other cable I can tap into for the power.

The car is a mercedes e270 elegence 2003 model..

thanks alot