When Neal first sees his birthday gift, a red BMW convertible, the music wanders to the same few notes as in Back to the Future (1985) (also written by Bob Gale) when Marty opens the garage to see his new truck.
When the movie starts and the two guys are discussing mythological wish-granters, there is a small sign on the bar wall that says "I'd rather be driving a MW." The "MW" is from the "BMW" logo, with the "B" missing. Later, when Neal (James Marsden) is driving his new car, the logo has the "MW" missing.
The character of O.W. Grant is a compilation of many different trickster figures in world mythologies. It is stated that he is half-leprechaun, which is shown in his red hair. Also, the monkey pipe is a reference to the Monkey figure of Eastern mythologies. The pipe's smoke can also be interpreted as a reference to Djinni.
When Neal (James Marsden) and O.W. Grant (Gary Oldman) are approaching Interstate 60, O.W. says, "There's a signpost up ahead." This is a famous line from the beginning of every episode of The Twilight Zone (1959).
The number of the building where Neal has his appointment with Ray for the delivery is 555, a reference to the fictional exchange for phone numbers in various movies and television shows. ("555" is reserved for phone company testing purposes, and no actual numbers exist using it in any area code.)
As mentioned in the movie, there is no Interstate 60 in the The Dwight D. Eisenhower National System of Interstate and Defense Highways in the United States. If there were, its eastern end would likely be north of Raleigh, North Carolina (Interstate 40), and south of Richmond, Virginia (Interstate 64). Its western end could be south of Monroe, Utah (Interstate 70), and north of Barstow, California (Interstate 40). Of course, it might not necessarily be nearly coast to coast either, but just to give an idea.