In the episode "Superspy", set in the 1940's, one scene that takes place outside Los Alamos, in the US state of New Mexico, clearly shows a vehicle with a license plate for the US state of Arizona. The plate design is also one that wasn't available until 1997.
In the episode "Superbomb", the courthouse scene is supposed to take place in Washington, DC, USA, but the building clearly says "Maricopa County Courthouse, 125 W. Washington", thus giving away its true location: downtown Phoenix, AZ, USA.