I used to get that all the time. The alpha tomcat of the 'hood was attracted to the heat from the bonnet scoop, Multicrop "keep off" cat repellent (placed on the ground around the car, NOT the paint) works. But you do have to replenish it every couple of days.

Anyway, there is a psychotic old bitch that lives a couple of houses away. Her cat was savaged by the alpha tomcat (I found a collar with cat fur and flesh in my garden bed) I have reason to believe she took care of that particular cat, cause I haven't seen it again..