I was gonna use a wiring harness for an amp and sound procesor install. I didn't wanna cut any factory wires. But I found out that the Metra harness{FRST} I would need is about $180 and it has it's own LCD screen that needs mounted somewhere for viewing the satellite radio stations. I have Sync, satellite, and SWC. I want to retain all these functions. So my question is can I cut the factory speaker wires only and retain the Sync, sat, and SWC? My thinking is yes but want to confirm with someone else. Please correct me if I'm wrong. Thanks.