Cat claws are not sharp enough to scratch a decent paint job.
I've had cats all my life, and seen them scratch all kinds of things, from trees to furniture, but never make a dent in automobile paint.
I just don't believe it.
They need to be able to dig into something soft. Then, they can rip it to shreds. But something hard, they just paw at it pathetically.
My favorite cat tries to follow me when I go to the bathroom, and paws at the door trying to get in, and never leaves a mark on the door. My favorite chair she's clawed to pieces.
You are simply wrong. I have seen it happen AS THE CAT DID IT. We're not talking about them intentionally sharpening their claws--just walking, or worse, jumping quickly off as they were scared. And we aren't talking about some crappy hundred dollar paint job, but the original paint.
Don't believe it if you want, but I'm not making it up.