If the first post in this thread is accurate, the newest spy satellites have resolution of 3 cm, or a little over an inch. At that resolution, it wouldn't be able to read a license plate. How many plates have you seen with characters over an inch wide? By that, I'm referring to the width of things like the vertical line on an "E". On most license plates, features like that are perhaps 1 cm wide. Now, the "Falcon and Snowman" story took place in the 1970s, so I really doubt they had much higher resolution then than we have today.

To the best of my knowledge, TRW never operated imagery satellites. According to "Deep Black", they were involved in the ELINT side of the black world. Boyce may have compromised that capability.

Imagery satellites are in LEO sun-synchronous orbits. They are only visible over a given area for at most a few minutes, so their ELINT gathering ability would be somewhat limited.