A .410 would be even better, fewer pellets to fly around, or a .44 mag with shot shells might work too. Actually I hate to see cats being shot. I have a huge group of black birds(starlings to some people) around here and cats do a fair job of keeping them down.
Every other day I have to wash my vehicles because of bird crap, and not just a little, but gops of it.These birds are protected by law, so I can't shoot them. Birds carry deseases and spread them around. What's so hot about birds that this guy wants to kill cats for them? I like birds and cats, but if I had to choose between being over run with cats or birds, I would choose the cats!
I have yet to see a cat climb on my car and take a dump!
I've seen thousands of cats climbing on cars and scratching the paint--some to the extent that the paint scratches were so deep they rusted, because one cat on top of a car is often there because another chased them up and they fight on the cars for the warm spot! And I know of at least one Mustang that was permanently put out of action (the car was sold, it reeked so bad) because a cat peed in the vent trap on the dash.
I'm sorry, but a cat pissing away a perfectly good Mustang or scratching up a five hundred dollar paint job does not make me particularly well-disposed to them. That a single member of the cat community as a whole f'ed up a Mustang...makes me furious thinking about it.
Now, if it had been a Mustang II, I'd have been all for finding that particular cat and awarding him his own desert and aquarium.