It's much easier swap it out with the bumper off, RealOEM shows it's common across all E39's so you shouldn't have any problem picking one up

http://www.realoem.com/bmw/enUS/part...&q=64546921946

The rolled up paper test is for the viscous fan (usually if not always on the water pump) and behind the rad. The Auxiliary is in front of the rad. (Just in case your referring to something else)