Backy-back
The two back seats of a station wagon which face the back end of the car. This type of seating was discontinued due to safety issues.
The Volvo station wagons have backy-backs from the late 90's. A specific example of this type of seat can be found in the Volvo 850.
backie back
The backie back is the last row in a large car. First you have the front, then the back, then the backie back!
Jeremiah, if you keep kicking mommy's sear, then you have to sit in the backie back!