The unmarked Pontiac Gran Prix is shown exiting the underpass at the Queen Mary to join the opening pursuit. Several shots later it is seen swerving out of the same exit from a different angle.
When Carl tells Gibbs that if Maindrian puts one scratch on his car, he'll kill him, the background shows that they are actually driving past the Queen Mary on the opposite side of the seaport, rather than down Queensway Drive where they are supposed to be.
Sgt. Hawkins hits the back of a disabled unmarked Pontiac LeMans just before his car rolls over. Later, Merle and Farley are shown rescuing Hawkins, his passengers, and the detectives from the LeMans, but the LeMans itself has disappeared.
The unmarked Plymouth Fury stalls in the warehouse at the start, then is pushed out onto the loading bay and smashes through a truck. In the next shot, it is still sitting stalled inside the warehouse in the background.
The blue unmarked car that crashes into the boat at the start can later be seen at the warehouse, with the same two detectives driving, even though they fled the vehicle after the crash and into an ambulance.
The opening chase takes place entirely in Long Beach. While Captain Gibbs is an LAPD captain, he initiates the pursuit because he is on scene and witnesses his daughter's fiancé's car being stolen. However, the majority of responding units are from the LAPD instead of the Long Beach PD - and these LAPD units are parked in various areas around Long Beach, where they have no business being, particularly at the Queen Mary. All of the detectives who respond are part of Gibbs' auto-theft unit and it is highly unlikely that all would be in Long Beach at the same time working on different jobs. The dispatcher even says that "assisting units are Long Beach PD." Long Beach PD would be the primary pursuit agency, with assistance from the sheriff's department and Highway Patrol (as in the film). Captain Gibbs would be the only LAPD officer involved, as the other detectives and marked units have no jurisdiction in Long Beach.
Ambulances do not join in and respond to police pursuits. Also, the ambulances are Los Angeles Fire Department rescue units, one of which is stationed outside the security office at the Queen Mary. As the Queen Mary is in Long Beach, there is absolutely no reason for an LA ambulance to be there.
In the film's opening car chase, the LAPD dispatch reiterates the stolen car's registration plate as "Uncle - David - Ocean - Nora - Ocean - Mary - Edward", but the registration plate is "UDUNOME", not "UDONOME".
The unmarked Plymouth Fury has no back window or rear view mirror, and would therefore be unroadworthy. It certainly would not be put on the street as a police car.
Several of the unmarked police cars in the riverbed during the opening chase have rotating lights on the passenger-side roofs, despite there only being one officer inside driving who could clearly not reach all the way across and out to the roof on the other side of the car to put them on.
End of ramp visible when Sgt. Hawkins' Torino overturns in the riverbed.
Captain Gibbs reads the Brickland's license number as "Union David Ocean Nora Ocean Mary Edward" - "UDONOME". It in fact reds "UDUNOME", and should be "Union David Union Nora Ocean Mary Edward".