it did have a rear speaker....thats why it had the control in the dash. R35 is a stereo radio... NO control in the dash. The control in the dash is to split the signal between the front and rear speaker...it's an L-pad control. Thats a mono source control, not stereo. Stereo radio with 3 speaker dash had a splitter under the dash that fed all 3 speakers. I dont remember if they had rear speakers with AM-FM stereo radios....every factory stereo radio in a mopar i saw back in the day had a front speaker for one channel and a rear for the other channel, or the 3 speaker setup in the dash. No 4 speaker setups that I can remember, at least in 70-74 or so. I guess you could obtain a single source signal from the splitter that fed the center speaker, run it thru the L-pad and feed the rear speaker that way, but dont recall if they did that.