The only car that should have portholes on it:

But, I do like the portholes on the Enclave. Very dramatic and they don't stick out as the others do:

For me, if I were to go with portholes, I'd go with the square ones on the Bonnie. But that'* just me

Functional is a different story, go for it.

I liked 'em at first. I thought they would be cool on my Bonnie, but then all of the sudden they are on everything, which really degraded their appeal to me.