Found hanging out of the bottom of the stereo in the 914. Someone decided to splice the red and white pre-amp lines (shown here) onto a "fresh" set of RCA plugs. Unfortunately it appears the only means of affixing the ground and signal feed lines to their counterparts was via twisting them together.
Gross. Maybe this explains why the left channel would go quiet every once in a while.
P.S. Snip snip, and the mess is gone.
Well, that explains that tingling sensation in my pants when I drive your Porshe...
Actually, that's Rob's Dutch Rudder from the comments on the last post. You'll have to ask him about it.