Thanks, Gilly, that's helpful information. I think I'll poke around my stepfather's 2000 ML430 or my dad's 2003 ML350 to see if I can tell how the LATCH anchors are mounted. I'll bet your right that the frames have been beefed up in LATCH-equipped MLs since now the seat frame has the exlusive responsibility of holding the car seat in place, rather than the vehicle's shoulder and lap belts. I suspect once I made all the changes that were necessary, it would be easier (and probably chaper) to just sell my '98 and buy a comparably equipped '00 or '01 model. But I really love those tr-folding seatbacks and I just bolted on a nice set of 17" ML430 wheels, so I think I'll just leave it alone for the moment. Thanks again, though.