Hopefully he still shows up, I have been through various worried periods with my cat Simba myself. He was hit by a scooter once when he had a broken pelvis, luckily he fully recovered. He's now 9 years old and still full of life!
One time he was missing for nearly two weeks, I called the local animal ambulance service, send them pictures, put up a message on a lost animal website, put up posters in the neighbourhood. Eventually I found him locked up in storage building nearby my home. My ensurance paid for security costs as every night the alarm went off and security personal scanned the building on several occasions. He was full of dust, scared and so very happy to see me!