Plot hole: After everyone flees the family home, as Optimus is escaping he is pursued by a helicopter. He is driving down a road in a straight line. He never deviates. Yet the helicopter misses him every time, only narrowly hitting him on the side.
Continuity mistake: At the end you see Bumblebee driving in and in the far away shot you see him drift/stop in front of Cade and everyone but next shot you see him drive in again and transform.
Revealing mistake: As the flat bed trailer hits the Winnebago, the stands holding the motor home stable are visible.
Continuity mistake: As Shane is driving to escape the Black Ops cars, he drives through a chain link fence with a private property sign on it. A second later, he hits it again.
Answer: Optimus was being dramatic when he said it contained their memories. Transformers don't carry their memories in their spark any more than humans carry theirs in their soul.
MasterOfAll