The amount of damage of the windows and headlights on Homer's car changes throughout the finale.
When Homer races to Central Park to pick up his family, he scratches his wheel against the carriage which emits sparks. In the extreme close-up, the front grill of Homer's car is missing.
When Homer attempts to leave without his getting his car towed away, his car door he opens has no window or door post. But when he first stops to get his car boot off, the car door now has changed with a window and a door post present.
The damage on Homer's car from his car boot and the jackhammer process changes sporadically.
Before leaving for New York, Homer throws his wallet in the fireplace. Later, as he's taking a cab to the World Trade Center, he pulls the letter from New York out of his wallet.
When the original World Trade Center was still around, the North Tower had a 360 ft. tall TV antenna on the center of its roof which was installed in 1978. However, at the moment when Homer discovers the restroom to be out of order in the South Tower's indoor observation deck, he rushes himself over to the North Tower where it is noticeably missing. It's worth noting because all other shots of the roof in this episode show it.
Homer should have called the police because Barney stole his car, as borrowing something and failing to return it is considered a form of theft.
In the flashback scene, The Empire State Building and The World Trade Center appear to be right next to each other. But the WTC was actually 6.1 miles away from the ESB.
Upon arrival at his car, Homer discovers it has been issued many parking tickets and has been wheel-clamped. While waiting for parking officer to come remove the boot, Homer drinks an excessive amount of crab juice from a food vendor and needs to urinate, but is afraid to leave his car behind. He finally goes to the restroom at the World Trade Center. While he is at the urinal, the officer arrives at the car and, finding no one present, issues another ticket and leaves. This could've been avoided if Homer urinated in one of the empty crab juice cans in the privacy of his car.
But if Homer had done this he would have been arrested for indecent exposure and public indecency.
But if Homer had done this he would have been arrested for indecent exposure and public indecency.
Marge states she can see fourth avenue in Manhattan. There is indeed a 4th Avenue in Manhattan. However, it only runs between 8th Street and 14th Street.
When Homer gets out of his car to jackhammer off the boot the sound of his car door slamming is heard. In the next overhead shot his car door is open. Subsequent shots show the door closed.