I'm not to sure about the VL.... if thats what your referring to even tho this is the VR-VS forum...
I was just working on my VP today as having been dealing with an overheating issue...
On my engine, Series 2 V6, One is just above the starter motor on a "Square" block coming of the engine block.. With a flashlight you can see it from undernear the car... Barely.. The otherside is in a mirrored position as well.
With the V6 one, There is a little red thread/ring/marking around the first thread or two of the bolt.. So if clean you can locate it by that.
Look for two plugs that are the same of both sides of the engine and dont actually bolt anything onto the engine itself. Otherwise the manual should have some useless diagram of it but not where.