Oh OP, I would feel exactly the same as I love cats.
I remember a few years ago I was driving to work at 6am and I had to swerve as there was a cat lying in the middle of the road that was dead and he had obviously been run over. It was 6am when I drove past the cat so I assumed it had happened overnight but there’s no way the driver couldn’t have known they’d done it, and I was so upset the cat hadn't even been moved to the side of the road. He was so badly injured 😞
I pulled over and wrapped him in a blanket from the back of my car and moved him and put him under a nearby hedge as it was too early to knock on doors or take him to a vets, and I was in my way to work, but I did take the cat’s collar off which thankfully contained his owners details. When it was my break time I phoned the owners and explained what had happened and it was heartbreaking 😞 But they went to collect their cat and they were so glad to have him and be able to bury him, and that night on my way home from work I took the cat’s collar to them which also meant a lot to them.
My friend’s cat was ran over and killed a few months ago and she found out when the vet called her as her details were found in the cat’s microchip. He’d been found in the road whilst still alive and the couple who had driven past him had bundled him up in their car and taken him to a nearby vet in the hope he could be saved but sadly not. It meant so much to my friend that the couple had stopped and tried to help. They had left their details with the vet, who passed them on to my friend, and when she spoke to them it gave her such comfort knowing that her cat had been cared about by strangers.
What happened was an accident but you acted compassionately and that will really mean something to the owners. I have a cat and if God Forbid she ever gets hit by a car I would find such comfort in knowing that the people who did it, or the people who found her, cared enough and were humane enough to want to do the right thing and felt like she mattered.
As has been said, this is a risk with having outdoor cats, but knowing that you cared enough to stop and get help, and that you wanted to get her to the vets and the owners be found will bring them some comfort, because it shows that you know their cat was important, it was valued and it was loved x