RE: Removing the lower grill
I'm going to assume from what you are saying that the lower grill still has
the original factory attachment or at least the replacements sold by VW.  If
you get in and look real close you will see a square plastic retainer with a
small round part in the very center.  That is a wedge that spreads the part
of the retainer that has gone through to the back side of the sheet metal.
To remove the grill you push that round peg/wedge through and out the back
thus releasing the retainer.  If you go to your local VW parts department
for replacements they now provide a screw to use instead of the little round
push in pins/spreaders.  At least mine did.
A crazy setup, no?  BTDT