I installed the Flash2Pass motorcycle transmitter module today and thought I'd share some details of what worked for me. This is a 2009 model and I was unsure of which side would be the easier or more accessible option so I started taking of all A-B-C-D panels and I found that the right side/battery side was both easier to access and work within. I never did get the left side upper panel off. Very frustrating for me.
However, once you're into that space you can see the bulb and connector. I pulled the connector off to make it easier to work with.
There are (of course) three wires, black, yellow and green.
I cut back a bit of the heavy tape wrapping to expose a bit more wire to tap into.
Using the supplied connectors I attached each lead from the transmitter module to the two outside wires, the yellow and black.
Don't make the possible mistake that I almost made by attaching them where the transmitter leads would feed forward into the bulb terminals. flip the socket over so that, when the socket is connected back to the bulb the taps then face rearward. Otherwise you'll probably have to unscrew them and re-install in reverse.
Finding a nice attachment spot for the transmitter also presented a challenge. I decided to attach it to the lower portion of the steel frame piece in the center. A little double stick tape to temporarily hold it in place and then the supplied zip tie. I also just lightly wrapped the excess wiring around some other wires in these to allow some slack for future service.
Hope this helps someone in the future. These are really great and convenient units. Super easy to program to the receiver as well. Best of all there's no fussing for the remote, opening the little glove box door, etc. Just roll in, flash the high beams twice and up the door goes.