Cat hit by a car

Question
After my son's baseball game we were driving home down a busy street.  I saw a cat heading across the street, but apparently the car in front of me didn't.  They hit the cat and of course they kept driving.  I stopped out of complete shock as the cat was flopping helplessly in the road.  I didn't know what I was going to do, but couldn't just leave it there.  Amazingly there was no one behind us and I was able to get out to the cat without danger to myself.  Just as I approached the cat, it stopped flopping, did not appear to be breathing and eyes were wide open.  I was worried to pick it up, but couldn't leave it there...so I moved it to the side of the road.  Again, I checked for breathing...nothing noticed.  I petted the cat as if to calm it...knowing in my head it was already dead.  There was not a lot of blood and the cat's body did not look damaged from the outside.  I can not get the image out of my head.  My son was so upset at what he had seen happen right in front of us.  I told him the cat didn't feel anything and that it was most likely killed instantly and that what we witnessed in the cat flopping was more likely nerves and less likely that the cat was in pain and unable to move...I guess I need someone to reassure me as I can not stand the thought that it suffered even though it was so quick.  What are your thoughts...do you think it suffered and was there anything that I could have done differently?  

Answer
Julie, I am sure there was nothing more you could have done.  It sounds like the poor cat suffered either brain damage or internal injuries or both to have died that quickly.  The cat was in shock immediately upon being struck and was not aware of any pain.  I am truly sorry ya'll had to go through that.  You were very kind to stop and try to help and move him out of road.  Think about it this way, sometimes a quick death to a stray animal is better than a lifetime of illness, disease, mistreatment, etc. out on the street.  Hope this helps.