I installed mine today. Very easy to install. Making a channel for the wire was the most difficult part. And by difficult I mean not very. I didn't have a Moto Tool handy so I just used a rat tail file. Doesn't take much filing on the lip to give the wire some clearance.
I didn't even bother fiddling with that white connector clip. Once you stuff all those wires back down in there, they aren't going anywhere. I guess you could wrap a tie wrap around them all if you were worried.
One of these days I'm going to remove that brace that separates the "storage" area from the rear section. That's valuable storage space back there! You would have to relocate that one electronic doohickey though. It has "UP" embossed on the top so I'm assuming that is the tip over/shut off device? I also wonder if it has to remain in that same left/right posture. If you turned it 90 degrees and mounted it to the side then did a wheelie or a stoppie, would the bike shut down? Sorry, just thinking out loud.
I mounted my light a little different. I trimmed a 1/2" wide piece of 3M foam tape down to about 3/8" and ran it over the entire length of the light. I went ahead and installed the light with the rubber gasket just showing from the top. Then put the stock light back in. I do have faith in the 3M tape on a smooth surface but I'm leery of that rough plastic. I'll give it a try. You do have an option of making an aluminum L bracket and mounting the light with some hardware. The LED light chassis has two threaded holes in the back of it. If I had an XC and was going to be bouncing down a trail I might think about that.
I forgot about the feature of the momentary pulsing light once you apply the brake. It does get your attention. Did anyone mention this sucker is BRIGHT!?