I placed mine snug on the headlight ... and then added a rubber strip on the fairing's headlight opening. It's been setup this way for approximately 8 or 9 years.

I've had mine mounted within 1/8 inch all around for 6 -7 years with no issues at all. As long as it is solidly mounted and doesn't move you should be fine. I do like the idea of a rubber strip around the opening.
