I am not very familiar with this unit. I do have one question though and its driving me nuts. If the previous owner of my car ran a sct handheld on it and got it tuned. Did that SCT "marry" itself to the car? If it did and he didnt unmarry it, that sct would be useless to him right? My main question is though, could i buy another sct, and well, marry that to the car as well? This is all theoretical...