One problem related to air bag not deploy has been reported for the 2000 Jaguar XJ. The most recently reported issues are listed below.
Collision with other auto, front damage, bumper totalled with frame damage, hood and fender and air bags did not deploy, Jaguar has and will not inspect auto at body shop, adjuster {from insurance company} and body shop both said the air bags should have deployed, I think if there is a problem it should be resolved before anyone is hurt, fortunally in this case there weren't any injuries.