Cars with the premium sound package get a different wiring harness. Part of this is because the wiring for the two different sound systems is completely different. For standard, the wires run from the radio to the speakers. For premium sound, the wires ran from the radio to the amp near the trunk and then to the speakers.Just seems odd that they would have all the speaker locations in the dash and trunk but no wiring at all.
Bottom line, you're going to have to run your own wires.