Hey. Just had some great news come back. My shiny rebuilt 2006 525 Sx with exc gearbox and fully built 540 kit just got registered here in Illinois. The secret is to make sure you keep your old ktm plates and transfer them over at a currency exchange. The Michigan title that came with the bike clearly states "orv not to be registered for highway use". To my delight they easily transferred my older 525 plates to my new Sx. I just wanted to give any of you trying to deal with similar issues some hope, IT IS POSSIBLE!!