BEGAN NOTICING A SMALL WHINE IN THE DIFFERENTIAL, MORE OBVIOUS AT LOW SPEED. LEVEL OF NOISE INCREASED RAPIDLY. CALLED DEALER FOR AN APPOINTMENT 10/22/12 SAW THEM THAT DAY AND THEY VERIFIED THE PROBLEM. CALLED JAGUAR FOR AUTHORIZATION. NOTIFIED BY JAGUAR ON 10/23/12 FULL AUTHORIZATION TO REPLACE THE ENTIRE DIFFERENTIAL. DEALER ADVISES AN ANTICIPATED TWO DAY DELIVERY TIME FOR REPLACEMENT. NOTE: COMPLETELY SATISFIED THAT THE DEALER WAS HELPFUL IN SUCH RAPID AUTHORIZATION AND TURN AROUND OF REPLACEMENT PARTS.MY UNDERSTANDING IS THAT USUALLY A DIFF. FLUID ANALYSIS AND "OTHER REMEDIES" ARE SUGGESTED PRIOR TO A MAJOR COMPONENT REPLACEMENT. I ANTICIPATE RECEIVING THE CAR BACK FRIDAY THE 26TH, OR THE FOLLOWING MONDAY. THEY ALSO NOTIFIED ME OF A TAIL LIGHT RECALL WHICH HAD NOT BEEN DONE, WHICH I HAD NOT BEEN ADVISED OF BY JAGUAR. *TR