I always thought the way the 1971 Alfa GTV 2000 incorporated the shield shape in the horizontal grille bars was pretty neat. I also like the series 2 Lancia Fulvia sedan grille, which is very similar to the 1962-66 Toyota Crown. One snippet about the XD grille I remember is that the slats were designed so that above a certain speed the air would be deflected over the bonnet for better aerodynamics (the intake under the bumper being adequate at that speed) - something inherited from the Granada design.