Owen didn't come home empty handed from uncle Brandon and aunt Lizs house. He kidnaped Optimus Prime from Riley and Gavins penthouse retreat (their huge bonus room/bedroom). He loves trucks and transformers. After a couple of years little Liam can raid Owens room and reclaim the Prime. By that time Optimus might not look that good (Owen the destroyer), but I am sure there will be "more than meets the eye" (cheesy movie reference) when the time comes.