Scoped out the 2008 grilles at the dealer today, and they're a different shape than the 2004 X3 grilles.
But, the 2004 grille is constructed as all chrome, and if you pop out the grille, you can remove the black plastic slats and then the ENTIRE grille will appear chrome. Saw some pics of this, and it looked a bit too much 'bling' for my taste, but perhaps it looks better in person.