I bought one for my '08 SERK and when I traded it in I kept it for my new '09 SERG.
On both of these I used a small plastic cable clamp like you use to attach a wire down to a surface. I use the loop end of t cable clamp to go around my front brake line and then drilled out the bolt hole to accept the photo eye. I looped the cable clamp over the brake line and then threaded the photo eye into the enlarged hole. You can twist the photo eye a little to pick up more or less light.
When I back out of the garage during the day, the headlights modulate and when I pull into the garage just a few feet the headlights go on full time. I've been stopped under an overpass and had my headlights stop modulating and go solid. As soon as traffic starts the modulator kicks right back in.
On the SERK I only had the one headlight. On the SERG I have two. I ran the modulator in parallel with both lights and the modulator has enough amp carrying to do the job.
I also have a Back Off modulator for my Tourpak LED spoiler light. I didn't want to mess with the LED taillights so I used the modulator on just the LED spoiler light bar. This is a great effect and gets lots of attention.
As far as the headlight modulator, this too gets a LOT of attention. I feel for the money it's one of the best upgrades you can do to get into someone's line of sight and have them see you.
They are not very popular around here and that's a good thing. If everyone had them I would be just another fish in the pond.
I've also thought about getting one of the Back Off modulators and put it in my car and or truck on the third brake light. Having the third brake light flashing and then going on for 4 seconds and then repeating this pattern over and over again, seems to be a viable option even for my 4-wheelers. I'm not sure if they are legal for 4-wheel vehicles though.
Don't worry about the photo sensor, putting it down under the front fork tripletree is not a problem and for me it works great there. If you didn't know it was there, you would be hard pressed to spot it; and then you'd have to be on your knees to see it.
