Hi, I am looking to convert my 1998 STS with bose from a non navigation unit to a navigation head unit. I have found a head unit and I know I can get the antenna and do the install but I do not know where to get, nor have the capabilities to make, the adapter to go from non navigation to navigation. I am willing to pay anyone to make me one, or if I can be directed as to where to get one that would be much appreciated. Thanks alot.