Getting though firewall

[Wurzig-Drei]

I have a 1985 528e, and am in the process of installing an amp. I have done it before but in a honda. I was wondering if anyone knew where to go though the firewall to run the power cable. Also when i installed the head unit, there were no wires for the rear speakers. Are the rear speakers spliced into the front ones or what is going on. Thanks for any help.

[El Presidente]

not too familiar with the 528, but my guess would be somewehre along the firewall on the passenger side. If your car is lacking speaker wires, it is becuase they have been cut.

[Scarface]

If you can't find a hole, make one, I have had to drill through the firewall numerous times...As far as the speaker wires, hmmm if there are no wires up front or they are spliced into the front ones, you may have a common ground system, which means running an aftermarket radio will require running new speaker wires from the new head unit to all speakers in the car..