Belac

using sonic stage v2.0 to record on my mz-n707 in SP mode when i play it in my car mdx-c8970 it only plays in the front channel. LP modes dont seem to work in my car, it sees the track and playing -timer is counting- but there is no sound so i am assuming that my car unit only recognizes SP but i dont understand why it is only playing on the fronT channel??!! how can i get it to play in all channels? read on another post that i might have to use the optical cable??? only hearing music in front channel sucks, PLEASE help if possible