Transformers 4 won't begin filming for several months but already there is plenty of speculation about where the movie will be shot.
Several movie trades and websites have been reporting the movie will film in various locations in the U.K., including London, Thailand, and China but, after Mark Wahlberg appeared in Chicago, IL this week t0 promote Broken City, local media outlets are reporting T4 will actually be filmed there this summer. One source even reported hearing Wahlberg, who is set to star in Transformers 4, ask around about rentals in the Chicago area.
It wouldn't be a total surprise if the movie spends time in Chicago since Michael Bay spent several weeks filming Transformers: Dark of the Moon in the Windy City in 2010. Most likely, Transformers 4 will be shot in several locations which means the rumors about shooting in Chicago, London, and China could all be true. There have even been rumors scenes for the movie could be shot in Austin, TX or Atlanta, GA, too.
Guess we'll have to wait for an official statement from Michael Bay, luckily he's good about stuff like that!
Source: Aaron, Transformers Live, My Entertainment World