I installed the BMW LED Supplemental Brake Light on my 2011 R1200RT this weekend. I ordered the light from a dealer and ordered the model specific wiring harness. As reported in many threads, there are no installation directions that come with either the brake light or the harness. Based on reading several threads and after scratching my head for a while, I think I figured it out for my bike. The biggest question I had was whether or not I had to drill holes in the rear fender. I decided that it was necessary to expand one hole in the lower fender (beneath the license plate where the wire in the new brake light lines up exactly over an existing hole) and to drill a new hole in a "well" in the upper part of the fender (in the back corner under the passenger seat) that looked to me like the intended spot to drill a new hole in order to route the wire to the space under the seat (the well is best seen from the underside of the fender by laying on your back and looking up at the underside of the fender; this wells seems to provide weather protection to the area under the seat since the well is slanted and I also filled the well with 3M putty after I routed the wire). Unlike some of the previous installations, I did not have to remove any wire insulation from any of the existing wiring on the bike and I did not have to soldier anything. Instead, the wiring harness "piggybacks" (two connectors) on the connector that goes to the passenger power plug and the third connector is a male/female spade that hooks to the tail light wire (right next to the brake light bulb) and the existing tail light wire then connects to the new spade. Once I got the guts to drill the new hole, the actual wiring was simple. This photo shows where the spade on the new harness connects at the brake light bulb.