Here is a link to a good thread
https://xoutpost.com/bmw-sav-forums/...ation-pdf.html

This will show you clearly all the pieces you need (and how awesomely beefy it is - it saved most of my rear end in a collision recently ).
https://www.ecstuning.com/b-genuine-...e/71600009711/

This is the wireless controller I got. No issues and no wire running. I have it permanently mounted to my race car hauler.
https://www.etrailer.com/Trailer-Bra...ha/TK94FR.html

Snagged this for the 4-wire tows (no brakes on these ones)
https://www.etrailer.com/Wiring/Tow-Ready/TR20141.html

__________________
Daily Drivers:
- 2008 535i, 320,000km
- 2004 X5 4.4, 01/2004 production, 420,000km
- 1997 328i, 350,000km

Track:
- 1996 328i, track/race car, ~300,000km

Winter:
- 2013 Ski-Doo MXZ X 800 E-TEC, trail can
- 2007 Ski-Doo MXZ Blizzard 800 HO
- 2001 Ski-Doo MXZ 600 w/800 engine, exhaust
- 1978 Ski-Doo Olympique 340 (vintage race sled)
- 1977 Ski-Doo Olympique 340E