LATCH is only good up to a certain weight limit, and it is VERY possible to get a carseat with a higher limit than that. The Clek Foonf, for example, has a FIFTY pound REARFACING limit, and a SIXTY-FIVE pound limit front-facing. After that, you can get a five-point harness booster that is fullback up to ONE HUNDRED pounds. You definitely can't use the LATCH anchors that long. I'll be getting the Foonf for my new car, because it's one of the best seats on the market, with the highest rear-facing limit.
Basically, Ford should have added in a measure to turn the airbags in the seatbelts off.