Really? I've always pronounced it car (kar) because it's short for character which is pronounced karakter in the first place.
Likewise I say char as "car".
I wish I knew the formal phonetic symbols of these, but I don't. But disambiguating these is just what they're for.
Car rhymes with are, or charge.
And care with pear, pair, hair, etc.
But I'm Australian, so I talk funny.