
So sorry to hear about the loss of your beloved cat.
As someone who has owned 3 cats, two being hit by cars, I can safely say I know how upsetting something like this is. In the defence of someone driving a car which hits a cat, I don't think you would necessarily know it had happened.
I remember once, years ago, I was in a car being driven by a friend, and a cat ran out in front of the car, which we then ran over. It was shocking - we were only teenagers at the time, but we scooped the cat up, and began knocking on doors until we found out who the owner was. Obviously they were distraught, but at the time it was the best we could do. Will never forget it, it was awful!
We had two brothers as kittens, who came from a farm (took the 2 we could catch in the barn!). At around a year old, one was hit by a car, and he managed to jump into our bedroom (GFF). He had a back leg pinned & lived to around 17. We then moved to a rural location, and within 2 weeks was knocked over and killed instantly right outside our house. He had been sitting on the back of the sofa behind me right before this, and I was upset for ages - he was the fluffier and cuddlier of the two, and also the one who would take on the toms in the area, protecting his brother. They were called Bill & Ben. We now have one female tabby, Freddie, who is around 19 yrs. She came as a kitten from the RSPCA, hardly goes out & can't be long for this world.
Cars and cats definitely don't mix!
So sorry for your loss once again, my thoughts are with you.