When the Mayor of Bakersfield rescues our heroes after their truck is overturned in the desert, they all board a white Chrysler Caravan. As it peels out, it is obviously an early 1990s model. When they arrive at the refugee camp, it is still a white Chrysler Caravan, but now obviously a late 1990s model.
Jake fires his M203 grenade launcher at an attacking robot twice in rapid succession. This is impossible, as the M203 is a single shot weapon; it must be reloaded every time it is fired.
When the transmorphers start landing, Jake grabs his gun and he and Madison start running. They turn a corner, another transmorpher crashes down, and suddenly the background topography is completely different.
When Hadley and company are chasing the black SUV, the siren of the police car is different than when they flee from the SUV after a 'droid' appears.
When the phone first attacks the diplomat's daughter, the car spins out. The car is driving on pavement, but the close-up of the spin out is on dirt.
On an external shot of the police car chasing the black SUV, the obvious stunt drivers can be seen.
The transformation plant appears to be the same set as Edwards AFB.
The helicopter that Hadley Ryan climbs into is a Sikorsky S-60 Blackhawk. You can clearly see him holding on to a standard aircraft yoke with both hands. The only problem is, the Blackhawk, like all choppers, has a stick control in front of the pilot for the right hand (cyclic), and a lift control to the pilots side (collective). What can be seen of the cockpit doesn't even match that of a Blackhawk.
When the black, driver-less SUV is chasing the police car, a driver can be seen in several scenes.
The movie is supposedly centered in Bakersfield and Edwards Air Force base, which are 90 miles apart, and yet seem to be almost next to each other.
Edwards Air Force Base is supposed to be in the middle of the desert, and yet several scenes show cars whipping by on a thoroughfare just outside the fences.