I say Clair-a. And that's how it was being pronounced when we were reading the name lists and decided it was a good name. Then, last night, DH (who is half German) said, "You know, it's really Clar-a." (like in car) I was in shock, as I had never heard of such a thing.
I told him (playfully) that here in America we say "Clair-a." He said that in England and Germany (both countries in which he has family) it's Clar-a. Then I realized that here in New Jersey, it would be Clah-ra.... (I'm originally from the south). Obviously, we would need to decide among ourselves how it would be pronounced, but I also wanted to get some idea of the general public-- how most people she met would say her name.