It seems that Transformers 4 is winding up its Texas trip as production moves to Detroit, Michigan starting Monday. Extras are being notified about whatever roles they are playing and where to show up. No other details as extras usually have to sign NDAs (Non-Disclosure Agreement). The China set being built in the city is almost finished, complete with built-in "damage". Exactly what locations, their purpose and when TF4 production will be using them remains unknown but it will be interesting to find out as reports come in. Thanks to J1000 for the update.