Hey, guys.
Here I have roughly two questions about upgrading sound system.
I have 2006 4.4 X5 w/ navigation system and I want to upgrade my x5's sound system with DSP.
1)
Should I also work on the audio wiring harness? I mean... Do I need to change ordinary audio wires for premium sound system although I have navigation system?
2)
I found out that I need two subwoopers(part no.65138379378) and
amplifier for HIFI DSP(part no.65126940977).
Is it possible that a local dealershop simply changes the amplifier with DSP and install subwoopers? that's it? or... I need some more difficult labors?


p.s. I have one more stupid question. Does X5 with premium sound system have better tweeters in rear seats compare to non-DSP sound system?