Business cd upgrade

[Pilly45]

Has anyone managed to upgrade there sound quality using the original head unit, can't find much info any where, can't be doing with new head unit, the ones I have seen installed look pants.
I have the standard 6 speaker system

 

[Pilly45]

I found this

http://www.z4-forum.com/forum/viewtopic.php?f=2&t=24956&p=348349#p348349

Seems like a lot of work, but its the wiring to the original head unit that will confuse me

 

[bcworkz]

Info on the head unit wiring can be found here
http://www.z4-forum.com/forum/viewtopic.php?f=2&t=42371&p=599717

As the post you found indicates, the speaker fitment is non-standard, you need to be creative. OEM speaker data can be found here
http://www.z4-forum.com/forum/viewtopic.php?f=2&t=41138&p=579722

You will need either speaker out to line level converter or a compatible amp, beyond that, you can do whatever you want with amps and speakers. Note that the speaker grilles in the door of your car have no speakers behind them. Apparently some cars have the wiring in place for them, but others do not.

 

[Pilly45]

Thanks bc for pointing me in the right direction 8)