With production of Michael Bay's Transformers 4 underway, eager fans are showing up at the sets trying to catch a glimpse of the new cars. This photo was posted to Instagram of an E-Jet Concept Car parked at the current filming location in Chicago. Obviously, no one knows for sure if this electric concept will be one of the key characters in the film, but our fingers are crossed. A transforming concept car provides new possiblities, as we've already seen just about every other vehicle in the original and subsequent films so far (a Decepticon limo would be kind of cool too). The Wikipedia page for the film has a list of other possible cars that will definitely grow in the coming weeks.