Wikipedia's definition of a back seat driver totally fits:
"A backseat driver is a vehicle passenger in the back seat who is not controlling the vehicle, and seems to be uncomfortable with the skills of the driver and/or wants to tutor the driver while the driver is at the wheel."
I also suffered w/ symptoms like this for 12yrs before someone told me what it was. I just have to remind myself that when i hear anything that isnt there that its just the chemical misfires in my brain. NOT VOICES.
Lol@back seat drivers.....i sometimes comepare them to a librarian who sits there.... Comments on the books we take... She knows everything. .. Where every book is but doesn't know where the freakkin toilet is...