The CDC truck that transports Jack to the FBI has "HAZMAT" written backwards on the front, so it can be read easily in a rear-view mirror. However the "Z" is printed forwards, so it appears backwards when the word is flipped.
The date on the immunity document drawn up for Gregory Seaton states that it is the "second day of November, in the year of our Lord, and of the Independence of the United States of America the two hundred and thirty-first", meaning that the events of Day 7 take place between 8:00AM on the 2nd November and 8:00AM on the 3rd November 2007.
The coordinates Seaton gives for the warehouse, 32°44'23" West, 117°10'42" North, are nowhere near Washington DC, and in fact are non-existent (Latitude values are only in the range 0-90). However, reversing the longitude and latitude values (32°44'23" North, 117°10'42" West) yields a real US address, specifically, the San Diego International Airport.