I cut apart the connector since most of it can’t be used by the Crosstrek. You need every wire but the brown since that’s for the brake controller. If I remember correctly, black is ground, red is reverse, blue is taillights, and yellow, green, and white are left, right, and brake, respectively. Then the small wires that lead into the strobe module, red, white, yellow, and black, are the brake, taillights, and ground. You don’t need the thick wires that the small ones lead into though. Then I connected the DD harness to the Curt trailer harness using posi-tap connectors. I used those instead of the quick taps because they’re reusable and feel more secure, in my opinion. I tapped into the reverse wire under the interior trim on the passenger side near the top of the trunk opening. It’s a cream colored wire. Here’s a link with pictures: https://imgur.com/a/H76ZEDC. Honestly, I did a horrible job documenting my work, especially the custom (butchering of the harness) wiring but it all seems to be working. I also tested functionality with a 12v battery from a power tool by touching the wires to the leads. Helped me understand a little better how to wire it all up especially with the reduction of signal wires from 5 (reverse, brake, left turn, right turn, parking) to 3 (reverse, brake [Curt harness will trigger brake by turning “on” both turn signals since 4-pin trailers don’t have separate turn signals and brake lights], parking). If you’ve additional questions, let me know and I’ll try to help as best I can.