I've read all over the place while trying to install an aftermarket stereo into my 2008 Hyundai Sonata GLS that there's a "premium sound" option that requires a special wiring harness. I bought this wiring harness without thinking about it. If I have premium sound, I will need to buy an extra adapter, and if I don't I will need to cut down this harness and remove some transistors.
How do I know for sure whether or not I have this "premium sound" option?