Ever try to find out where that shrill "buzz" is coming from while you're cruising down the highway? It's an experience, but I found that a firm hand on my headlight quieted the noise. After less than 4,000 miles on my '07 FXDWG this mystery vibration/buzz showed up. It was pretty hard to ID but after patiently listening, changing cruising RPMs to get it to come and go..and feeling around very carefully figured it out to be the headlight mount. Apparantly a weld, or rivet on the bottom of the stock headlight bucket gave way or got loose and began to sing. A song that I didn't really enjoy too much. Fortunately this is covered under warranty, and will be a N/C repair. Interesting that the replacement part is not the same as the OEM headlight bucket! Obviously this part has been a problem and has been replaced with another part #. "Hey Harley, If you knew this part was going to go bad, why not replace it BEFORE I had to hang over the handlebars to discover it?"