(Tango1300 @ Apr. 06 2007,13:24) Nothing apart from the throttle linkage kit you can use that comes with the cruise. All the connections should be spliced and shrink wrapped. I sourced the Suzuki Manual and info here as far as which wires to tap. I owned my Hayabusa 2 days when I started my cruise install and the second day I was on my way to Annapolis from Houston.
As an indicator of how well it works... I rode 700 miles my first day, 460 the second, the entire 3rd day was spent taking the Blue Ridge Parkway and used the cruise very little on the curves.
Once the right dip-switch settings are found, the cruise control works seamlessly and I have never had a failure. Its by far the most useful mod that I have done to my Hayabusa.