This might just muddy the water....I "thought" that convertibles (at least b-body) got 3 speakers... BUT my car is coded for AM/8-track, so maybe I was wrong. I've never heard 3 speakers = am/fm or am/8-track
70 Roadrunner convt. street car
440+6, NOS, 4-spd, SS springs
'96 Mustang GT convt. street car
'04 4.6 SOHC, NOS, auto, lowered
"Officer, that button is for short on-ramps"