Learoy, do you mean you have the optional back seat? I think you can remove the seat cushion, and see what is underneath. If there is a compartment under the back seat, that is where you will put the Bose system in. I think the area behind the front seats was designed as a compartment so I won't be suprised that there are two empty compartments underneath your optional rear seats.

__________________
95 R129
04 Infiniti G35.5 BS
10 X204