One problem related to front seat belt anchorage has been reported for the 1996 Jaguar Vanden Plas. The most recently reported issues are listed below.
Right rear bracket that holds the drivers seat to the mounting track broke. This allowed the drivers seat to swing back on acceleration and swing forward, into steering wheel, when applying the brakes. The seat would swivel around on the three remaining attach points. This occurred during normal driving. If this had happened as a resujlt of a rear end collision, it is likely that the entire seat would have torn loose and become an unguided flying object in the car. Given that the seat belt is attached to the seat frame rather than the car's frame, it would have provided no protection. If the airbag were to have deployed, the force of it would also have knocked the seat, cocked at an angle and with the driver strapped in it, across the back of the car and into any passenger sitting back there. I have detailed photos on the broken bracket and the frame mounting from which it separated.