... I have no experience pulling these off, do they sit in front of or behind the actual windshield glass?...
Neither, next to it. The moulding slips over the windshield frame with the short edge just turned down over the metal windshield frame. Then the windshield mouldings butt-up against it to cover the area where the sealant is.
-=>Lee<=- Due to budget constraints the "light at the end of the tunnel" has been turned off!