It's been a busy day. I decided to install my trailer harness in the LR4 today after the roof rail install. It is straight forward using the info at https://www.disco3.co.uk/wiki/Owner_Information_Mirror although my harness was slightly different than the ones shown there. There's one bit I'll share to help make things go easier not shown in the instructions. The harness runs over the LR frame rail under the truck. There are two harness retainer clips in that location. Using a 13mm socket, remove the 2 bolts that hold the heavy damper installed over the frame rail. This allows it to be moved forward a few inches providing the room needed to attach those 2 retainer clips. I fought it for 15 minutes before giving in to this fearing it might be a PITA to get reinstalled. :banghead: