Thanks, guys. Jedinator, there are two rows of bricks behind the grille. The top row is made of regular bricks, bu the bottom row is made of headlight bricks. The tiles are attached to the recessed studs in the headlight bricks, and are pushed out by the top row of bricks. Hope that makes sense- just try it out for yourself.
"That guitar belongs to Peter Frampton!"
"Peter Frampton is dead and so are all of his grandchildren!"
"Then it belongs in a museum!"
"DR. JONES SIT DOWN!"