the door being closed is not going to prevent the door opening from deforming under chassis flex. you can still close the door when the z is on jackstands, you just have to lift the door up a bit. the door needs some space around it in the door opening to allow for chassis flex. if it was an exact fit, the door edges would scrunch up against the edges of the door opening, chipping the paint etc.
--.scubasteve.--
(Rebuild started: April 2004. estimated completion: sigh)