Salam brothers.
I have a VXRi 07, and i wanted to upgrade its music system quality by adding some sort of a woofer in a box that i usually see in other cultuses have in their back (i dont exactly know what it is called). There were a few questions in my mind which i wanted to ask you guys, please elaborate :
Can the company fitted pre in cultus support that woofer.
Do i have to install the amplifier with that also, or the MP3 player only would be enough to handle it.
Can anyone tell me how much that thing can cost, minimum to moderate level, and are there any other ways instead of that ugly box to install some good sound system in the back of cultus.
Actually i have to travel in the car with family mostly and dont want anything "shokha" or something, just wanted to keep the space and joy both at their best possible in my ride. 
Regards,