Kinda like in Transformers Prime with Mech, but just Mech. The idea of Earth's own Decepticons, an organization that is studying the remains of the Decepticons left over after the battle of Chicago to make weapons, but with bad intentions. Kinda like HYDRA in the Marvel universe using the Tesseract to build weapons Maybe a highway chase like the episode Convoy in Prime. Then a final battle between the Autobots and them. Then, maybe later on, they accidentally reanimate Megatron, Shockwave, etc etc, then it leads to the next film with the return of the Decepticons.