If you replace the double pane insulated glass with a single pane of safety glass, you'll have to have the molding and frame modified. Check with a couple of glass places and see if they are willing to remove window, take glass panes out, clean them and reseal them. Some will tackle it, others won't. If you search on line, you'll find a number of folks who have instructions on doing it yourself. You might find a window shop willing to tint the window when they take it apart and repair.
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI