hello guys, im writing from spain.

let's see if you can help me:
how can i enhance the sound of my Z3? ive got pretty poor speakers but a good mp3-radio, and i wanted to put some 6x9 inch speakers behind the seats and (why not) change the standar speakers of the front.
How can i do that? ive heard of someone that had these speakers behind the seats in a 2,8.
My car is a 2.2i roadster sport edition (same as your 2.3 i think)

Thanks!