Doug should have turned 40 last year. In the episode, "Precedent Nixin", Doug's parents use his birthdate as the code for their security system. He says his birthday is Feb. 9, 1965, which means he would have turned 40 in 2005, not 2006.
Arthur: Life is one long line, except at the end of it there ain't no merry-go-round.
Carrie: [Doug] can't be happy with his life, wearing short pants to work and dragging packages to people.
Deacon: You know I do the same thing?
Carrie: You said you were happy with your life.
Doug: Denial ain't just a river in Spain, honey.
Spence: Danny and I are going to check out the Haunted Castle.
Danny: Yeah, scared chicks are very approachable.
Arthur: (to gawkers) What are you looking at? You don't want to see a man in a wheelchair, then don't send him to Korea.
The German episode title is "Krise auf Bestellung", meaining "Depression Made to Order".
The theme park scenes were filmed on location at Six Flags Magic Mountain in Valencia, CA. While the name of the park was never mentioned (since the episode is set in NY), Goliath is the name the major rollercoaster at that park.
Deacon finally balks at pushing around an increasingly belligerent Arthur, declaring he's, "done driving Miss Daisy!" Driving Miss Daisy (the Oscar winner for Best Picture of 1989) dealt with an old, southern white woman and the relationship she forges over 20 years with her black chauffeur.
After Deacon tries to tell Arthur he's done buying him things, Arthur says, "getting Arthur what he wants, $100; getting your son to the front of every line, priceless." This is a play on the famous MasterCard commercials voiced by Billy Crudup.