This...
http://www.carseat.org/Legal/622_Latch.htm
Sorry to clutter your thread. It looks like they started installing them in 2003. Just found the info on them in a 2003 owner's manual but not for my 2002. They are mostly invisible, you have to poke your fingers between the cushions to feel them. Most cars that have them will have little buttons with a picture so you know where to poke your fingers in. Those white buttons on yours are what I am referring to.