Most of the stereo sales sites will have trim rings for specific years and models of vehicles. Your situation may be unique, as you are looking for a Kenworth trim ring. If you are installing it in an existing opening, you may have more success. You could take the radio to Best Buy or a stereo shop, and find a trim ring kit to fit your stereo and opening. They usually come with side attachments to connect to the vehicle. Then decide how you will install the stereo and the trim ring. Based on your description, it sounds like you are going to have to get creative. Without a photo of the area involved, its hard to give a specific response, just suggestions.