I purchased the hitch and the plug and play harness from Pierre last month and it was a complete dream to install. I did have his video on during the install and I paused it at every step. It did not take long at all and it was much easier than he makes it look.
My 622 is a 2014 and has the 4 pin square harness, the plug and play was 4 pin flat, Pierre suggested cutting a square apart and putting it back together, well that would be a nightmare.
A company called Wesbar makes a flat to square pigtail, their website can direct you to a dealer. It is a perfect fit, except the one I got had the green and brown wires switched, not a problem, I cut the cable and switched them, then heat shrieked them together again.
Now the trailer works behind other vehicles or my Spyder.
Joe