Have a small bio that kind of links in with the Japanese Binaltech story, or what I have read translated, it will make more sense later. While getting him online the Decepticons were rushing to bolster their forces and skipped many upgrades to his core programming including the ability to control and operate his new alternate mode. Formerly being a mini-cassete and a robot t-rex, did not prepare Overkill for driving when he was revived into the stolen Scion body of Skids. He also made "needed" modifications as well as salvaging his previous weapons from the rust. He struggles daily to learn to drive, since a huge walking robot isn't that hard to miss for the Autobots.