2013 sonata stereo

I bought a new head unit and the Metra wiring harness. It comes with two separate harnesses and they do plug into the factory harness. The problem is that the car's left harness with power and ground also has all the speaker wires. But, the Metra harness only has the power and ground wires on the left harness. The right harness contains all the speaker outputs. I don't understand how the Metra harness can possibly work when the speaker wires seem to be on the wrong harness. Am I missing something? I have posted a picture diagram to help explain what I am talking about. https://www.dropbox.com/s/xc4l1gun48ubwgy/Metra%20Wiring%20Diagram.jpg I have installed 4 or stereos in my life and common sense tells me something is wrong. The harnesses plug in, but all the speaker wires are on the wrong harness. I actually have 2 Metra harness kits and they are both designed this way. I would really appreciate some insight into this since my dash is all torn apart now.

sounds like you bought a harness for a factory amplified system when your car has just the normal system. its very possible there are multiple different harnesses for your car to integrate with different trim levels. personally i have never done any newer hyundais so thats about all i can tell you is this the harness you have?

stupid question but will the plugs fit on either harness? they look about the same and that might explain the issue because there could be more than one set of power wires. every harness ive found looks exactly like yours. theres no possible way that every company made the same mistake. also which audio system do you have in your car? they list a dimension and an infinity system too. if you have either one of those then i think it needs a special adapter.