> It's basically legal to kill people with a car as long as you aren't drunk or grossly negligent.
It's the same even without cars; if you kill someone by accidentally bumping into someone, or running them down with a bicycle, you aren't going to get charged with murder as long as you aren't grossly negligent.
Why do you want an exemption for cars?
Name one other multi-ton object that you can move through public spaces at high velocities without the law considering it inherently grossly negligent.