I managed to remove it finally but it gave me such a hard time to get the angle right. Also I used different torx sizes so I'm not even sure myself what size it was. It turned out that I have five screws on my back of the steering wheel 2006 with sports package. For the first three screws (lower and sides) I used torx 20 with no problems, but the last inner ones which are closer to the airbag I can't figure out whether it was torx 15 or 13 that got em undone. I think you better ask someone else to know for sure