Hi,
I had a very quick look on my FSI at the location indicated above but could not see it, too much stuff in the way and I did not have a mirror to hand.
There seems very little around on this, the best I could find does not auger well, read the third short post by someone who appears knowledgable.
location of G28 crankshaft or speed sensor on Golf 4...
www.volkswagenforum.co.uk
If you do the work yourself lots a pictures please and a 'How To' would be great.
Andy