Thanks - thats brings up another question. I found this when looking to buy the part online

http://www2.discountmbparts.com/parts/parts1/discountmbparts/wizard.jsp?year=2001&make=MB&model=E-320-006&category=A&part=Camshaft+Position+Sensor&dp=false

It looks a little different and is fairly similar to what Im seeing at the front of my engine but given that everything Im reading seems to indicate that its at the back of the engine im hesitant.