One could relocate the oem radio to the trunk and not lose the gongs. All the parts needed are available.
You'd need parts 1, 5, 2, 3, 9, 11 to extend the optical connectors. Then just extend wires for the canbus, power/ground, wires for a small speaker to hear the gongs, etc.
If someone would put together a kit to relocate the HU I'm sure people would buy it.