In an interview, Steven Spielberg said this was the third most difficult movie he has made in his career, behind Jaws (1975) and Saving Private Ryan (1998).
Besides the obvious Bigfoot, Delorean, and Akira vehicles, other notables in the race were the Mach 5, Batmobile, A Team van, V8 Interceptor, Christine, the Porkchop Express from Big Trouble In Little China and the Trans-Am from Smokey and the Bandit, the RV from Space Balls.
The spell cast to use the Orb of Osuvox is from the movie Excalibur. In modern Irish Gaelic, it's "Anáil nathrach, ortha bháis is beatha, do chéal déanaimh," which means, "Serpent's breath, charm of death and life, thy omen of making."
The Zemeckis Cube is named after director Robert Zemeckis. When the cube is activated, the music playing is from the Back to the Future (1985) trilogy, directed by Zemeckis. Alan Silvestri composed the score for both the Back to the Future trilogy and this film.
Parzival's belt in the Oasis has the Thundercats (1985) logo on it. The belt itself is the same style as Han Solo's.