The upper bushings on the front shock absorbers are prone to failure and may produce a rattling/jingling noise as the car is driven over bumps.Google+
Car Problem Reports
Jaguar Vanden Plas Rattling Noise Due to Failed Upper Front Shock Bushings
Jaguar Vanden Plas Problem
Average Mileage: 73,600 mi (49,000 mi - 98,200 mi)
Visitor, 1990 Jaguar Vanden Plas, 49,000 mi
I am experiencing this now and having struts & bushings replaced next week.