My wife drives a “Leaper” and I always say JAG-you-ar here in Charlotte, since that’s they way the folks who built the car (pre-Ford) pronounce it. However, since I’m fairly certain the animal does not reside in The UK I’m pretty sure they didn’t name the cat. So do you pronounce it like the people who named the cat pronounce it? I’m guessing that’s South American’s.
And then there’s always Austin Powers’ pronunciation… SHAG-you-ar.