If the garage door panels are wood then yes a garage door panel that is cracked could be fixed using wood fillers and glue.
Garage door exterior surface cracked.
Cracking due to poor compaction of sub grade before pouring a concrete slab it is important to prepare what is often called the subgrade which usually involves compacting the sub grade and base i e.
You are more apt to see these types of cracks on a garage floor that has a hard smooth troweled surface than one that has a broom finish.
Loss of caulk s initial adhesion and flexibility causing painted caulk to crack and or pull away.
Caulk paint cracking or crawling the cracking of the paint film over a caulked area.
Repairing the doors requires a little work and depending on how large the crack is could be.
The surface is also easy to clean but the door itself may break if you hit it with a car or tractor.
Actually fixing a crack in a garage door panel can be a difficult and even impossible task.
Gravel and or sand on top of the sub grade.