I dont know about the SP2 body, but on the Mugen, the front cut outs are all basically the same, even the engine cut out is in the same spot, the only differecnes are the cut outs on the "bumps" behind the shock tower, need to be approx 1/4" futher towards the back, to clear the shock mounts, and you need to cut around the radio box at the back, and the mounting holes are in different spots slightly,
did you try and mount it after or before painting? if you do it before painting, its fairly easy, just trim a little bit off at a time,
If someone else doens't by tongit, I will try and post a pic after work,