the big difference with the sh is there is a box mounted inside the engine bay that parts maufacturer's didnt really care for.... so they just acted as if it wasnt there... and well.. alot of things just wont fit in the prelude SH now because they wanted to use the space wehre ATTS is housed... and ATTS is nasty by the way, really can help your driving if you're a newb or have alot of twisty roads. if you meet either of those requirments get the SH, if not get another model