I have a a6 1999 and want to change the grill to the big mouth honey comb but don't know which bumper to use can someone help me please

 

if your talking about the really big grille i think those didnt start till about 2005 or so. You may wanna check around some junk yards or something first to see if its do able or not, bumpers change how they blend into the fenders alot between 99 and 05 so do some research 1st