1969 Road Runner coupes:
AM radio = 84.6%
AM 8-track stereo radio = 3.2%
AM/FM radio = 1.3%
NO radio = 10.9%
rear speaker(s) = 12.5%

I'd start another thread:
"Who has a '69 Lynch Rd. car with a factory rear speaker(s)? What fader knonb/location is on the dash? How's the rear speaker mounted? What's the speaker's part number & what radio was in the car when new?

Simple! Right?