Retrofitting from standard audio (no subwoofer) to HK

[muntes]

Hi all,

I have an XC90, I'm looking at retrofitting it to HK due to the fact I found one locally for 800$ with an amp and all the speakers:
https://ibb.co/0f1gPhR

Any idea what will change from the Standard audio system? Do I need to redo all the wires? Or just add the wires for the subwoofer?

Thanks