i have had know two occasions that a garage or spares shop has taken the reg and details to get the wrong part ordered.
first was the rear shocks thread not long enough
the other was a maf sensor put it on reved it hesiant revs
second one delivered same again
put old one on and ok apart from hunting idle
has anyone else had this prob with parts or is it ive got a 1.6 front and rs4 back