Self Installed Trailer Wiring/Hitch Info

[hopz]

Hello all. First post here, but have been lurking for a while. I invite you see the profile.
I want/need to install a trailer hitch on my 01, X5 and have determined there is no straight forward, simple DIY option. I am fairly experienced mechanically and in particular with BMW, having done restorations on 2002's and 5 series.
Also long-time BMWCCA active guy.
Much prefer to do a DIY project. I have the time, tools, and desire... but would benefit being in contact with any/all who have experienced this before.

I have seen the article on the hitch install, but wonder if anyone else has experience with Parking Distance Control rear bumpers vis-a-vis the Hidden Hitch option? Or any other non-OEM equipment.

Next, has anyone self installed any brand after market wiring harness for the 7-pin connector?

Next, I see the fine articles on the trailer brake controller install. These are great. Anyone else done it?

Thanks in advance. Looking forward to enjoying this forum.
Bob
(OBTW the hopz handle refers to hops in the beer....)