The name of the hotel Sam and Dean stay at is the White Star Motel which alludes to White Star Line, the owners of the Titanic.
The business cards and a book on the travel agents desk all feature the name "EJ Smith", the name of the captain of the RMS Titanic
The beer bottle in the first scene shows an image of an iceberg.
At the Travel Agency, there are posters on the wall for Detroit as "America's Top City" and one for Cuba. Since Detroit has been in decline for decades now and Cuba at that time was still under a trade embargo that barred tourist travel, this reflects differences in the new timeline.
Eric Kripke, the show's creator, originally envisioned the Winchester boys driving a 1965 Ford Mustang. In the alternate timeline, they drive a 1967 Ford Mustang fastback.