I'm trying to set up my sound system now for a 1990 mustang lx. I got a 4 channel amp that i want to run my speaker off of but first i need to get the power wire through the firewall to reach my amp in the trunk. I already tried looking at the other threads but all I could find were the newer mustangs. Does anyone have any suggestions or pictures of where they ran their power wire through their firewall. Anything will be greatly appreciated. Thanks.