2001 S8 front suspension parts
 

I need a front lower front control arm. The auto parts places list them, but they also list the 2001 S8 arm as being the same as a 1999 A8. I know this isn't right because I have both cars and the ball joint is a different size. It's much larger on the 1999 A8. Is the 2001 A8 the same as the S8 ? Anyone ? The part # on the S8 is 4D0 407 155 M. I'm thinking the "M" on the end has to do with the ball joint size...??? Are the front lower rear control arms the same as the 2001 A8 or same as the 1997-1999 A8 ?