they usually stay close to home if there is food available. They don't wander except for food so be sure to leave his bed, food and something that smells of you near the garage with the door opened a tad for him to get in. Also cats hid during daylight hours go out at dawn and when it gets dark and call the fur baby. You may have to do it a number of times over and over but that is the best time to get your furbaby's attention
can you leave the garage door cracked with the light off? food in there? check all the bushes/shrubs that are near your house, cats like hiding in the really dark/dense ones that sit low to the ground.