The vehicle can actually accomodate the latch system used for car seats. Unfortunately, once kids move up to the booster seat, all of the seats that I can find stop using harnesses that are incoporated into the seat. The booster seat basically just lifts the kid up a little bit and then you wrap the vehicle's shoulder harness around both of them. There are convertible seats that work as car seats and booster seats. You basically just take the harness off when the kid gets bigger.
I looked at some pictures of a 1992 Bronco, and saw that they had the harness attached to the top. The picture I looked at looked like it was actually mounted on the floor, inside the panel behind the seat. It looked like the mount on the top was not anything special, but I would be leary of just mounting the belt to the top without knowing if there is actually some additional reinforcement or soemthing.
Thanks for the info!
Ira