From memory it's near the middle of the engine at the back, accessible from the top with bonnet and plastic engine cover removed. If I'm not mistaken this sensor provides engine speed to the ECU whilst I think that engine position is given by the dual camshaft sensors.
Best thing is get the car onto a diagnostic computer using the OBD plug, on my LHD car just under dash on far left side. Bizarrely neither of the two BMW garages I tried could "speak" to the ECU on my car and it was a friend with his own garage and a multimake diagnostic computer who was able to get the info. The computer asks for the BMW model and we had to try a few V8 types before success. In the end we selected: 7 series, 1996-2001, Motronic 7.2
Hope this helps and if you need further info offline don't hesitate to send a pm.
Cheers
