Is there a torque setting for the lock nut on the front wheel bearing [the one with the allen key bolt in it] I have been told do up tight then undo it about 3-5 mm . Would this be about right :beer

Sand Kombi

these are not to be Torqued up. Otherwise the wheel bearings will not work correctly. overtightening will cause the bearings to over heat n wear out quickly.

the washer behind the nut is the key to the tighteness of the nut

The nut should be tightened so that the washer can be mooved slightly using a screw driver on the side of it, then the lock nut or lock screw can be tightened.

This applies to all cars wheel bearings for that matter not only VWs.

Can the car still be on the ground when adjusting the lock nut ,or does wheel have to be off the ground

The method I've always used (and my original 1970 bearings now have 248.000 miles on them so I know it works), is, with the wheel OFF the ground, tighten the large axle nut until the bearings just start to bind (the wheel slows when you try to spin it), then with the wheel still (so the bearings etc don't move) carefully loosen until the nut until it is actually loose, and then FINGER tighten until it touches the washer and just a bit more - a firm finger tighten.

Then tighten up the locking nuts and you are done.

This method takes out all the slack in the stack of assembled parts which might be present, by slightly overtightening first. Then the loosening followed by finger tightening ensures that there is no binding but no slack either.