Where is the Common Ground Splice

[Carbarns]

I'm installing a new head unit in my 87 325 and understand the "common ground" design.

Cheap lazy B... that I am, not wanting to run new speaker wires, I'd like to locate where the common grounds are spliced together.

They run out from behind the old receiver and off to the right behind the instrument panel. Do they spice down at the left front speaker or somewhere else?

Many thanks in adance!

[Starmavin]

The go into the amp in the trunk, you will be a million times better off running your own wires. BMW stock radio has only left and right output, you adjust the front to rear with the amp control above the raido. BTW buy a crossover for the front tweeters, they work really well, too well....