Jag-u-ar

        Being from the American side of the pond, I'd never heard this 
     until I ran across it in a bok called "Is There A Cow In Moscow? More 
     Beastly Mispronunciations and Sound Advice" by Charles Harrington 
     Elster:
     
     "Jaguar - pronunced JAG-wahr.  Do not say Jag-yoo-ahr, which is an 
     overpronunciation and a poor imitation of the British standard 
     pronunciation, JAG-yoo-ur.
     Webster's New World Guide (1984), which gives JAG-wahr, adds that, 
     'JAG-yoo-ahr is occassionally heard.' I have heard JAG-yoo-ahr in 
     commercials for the British luxury car of that name, where it struck 
     me as yat another example of the vocal affectation common in broadcast 
     advertisements for upscale products."
     
                                - from Olympic Brian