Metra 70-7301 Receiver Wiring Harness
2003 Kia Optima
Crutchfield Customer Review (What's this?)
Only shortcoming was not with the harness, but with the instructions that were sent for my car. A 5 minute call into Crutchfield support to let me know how to hook up the blue and blue/white wires resolved everything. Plenty of length without so much extra wire it was hard to stuff into the dash.