Air Horn Kit
I just had an air horn kit put on my '02GS Adventure done as a prototype for most oilheads. The sound is awesome, like a big truck, and right now! The kit will be put together by Rivco Products who have made many add ons for the chrome league of Hondas and Harleys. After many years of badgering (no pun intended as we are in Wisconsin) I had the owner, Rich, try a set-up for BMW's. I am more than satisfied in the result.
With the usual disclaimers I have no financial interest in Rivco but am totally satisfied with their product.
Rich took pictures and is trying to put together a kit for all oilheads, info can be found at www.rivcoproducts.com.