I would hit the cat. As a matter of fact I have already hit a rabbit and a cat this week. The rabbit was in the sticks so I felt really bad about that one because the rabbit was where it was supposed to be, however the cat was in the middle of a busy residential area.
BEGIN R ANT:
There should never be any domesticated animals hit by cars in an urban environment. That is completely the fault of an irresponsible owner and I don't feel bad at all when I run over ANYTHING. As a matter of fact, I hope the owners of the animal REALLY love that animal because they deserve to be unhappy. People need to take responsibility for their animals and take care of them like they deserve to be taken care of, which includes at the least not letting them run around in areas with traffic. When you keep an animal, it is entirely dependent on you for it's mental and physical well being. This includes: sustinance, sanitary and adequate living conditions, excercise, preserving their safety, etc... be responsible with your animals. END RANT
Anyway, I will go out of my way not to kill anything, even insects, so if it was possible avoid it, I would, but not if it means wrecking my car.