If you mean the two doors through which you gain access to the fog lights then you can buy them from NeedsWings.
Dave, I believe Phil is talking about those kinda square plastic box thingeys that have the 2 extensions that the belly pan clips into on the sides.
BTW, when I got my car, I noticed that those no longer 'clipped', I pressed the belly pan all the way up and drilled 2 small holes in the extensions through which I now insert cotter pins.
Been working fine for years now, no need to spread the cotter pins, they stay in just fine.