From new I was puzzled by the amount of oncoming drivers flashing their headlights at me - mainly because I knew my S-Type was fitted with auto-adjusting Xenon headlights.

I subsequently found out that the adjusters were intermittently adjusting the left light higher than the other - as shown by the image. This high light was blinding oncoming traffic and lighting up road signs well into the distance, while projecting silhouettes of the cars in front of me onto the sign posts.

The ONLY way to reset the Xenon headlights when this misalignment occurs is to pull in to the side of the road and restart the car.

I queried in an e-mail about a solution months after showing the problem to get this reply from Michel J. Tinguely, the Service & Training Manager for JAGUAR Land Rover Schweiz AG:

I had to wait until the new year while my Dealer "contacted Jaguar" before they attempted a repair at the next standard service. Since that repair the headlight fault occurs on a regular basis. These animations show the way in which the adjuster seems to bounce one light and often leaves the left light pointing too high :

See the following Movies in the Multimedia Section
lights_06_02_2005
bouncing_and_resetting - note left light bouncing.
18_04_2005_lights - note left light bouncing before returning lower than before.

18_04_2005_light,jpg 67 kb Picture taken just before above animation. Left light too high.