Elon Musk sure does like his movie references. The mind behind tunnel digging venture The Boring Company revealed on Sunday that he got the idea for the business model from Spaceballs. Musk, who has also placed references to the movie in Tesla’s lineup of electric vehicles, seemingly can’t stop quoting this 1987 classic.

“The real money comes from merchandising. I learned it from this documentary,” Musk said on his Twitter page, followed by a link to a scene from Spaceballs.

In the scene, Yogurt (played by Mel Brooks) explains to the characters where the money from the movie is made. A wall moves away to reveal a gift store filled with Spaceballs-branded products, including t-shirts, lunchboxes, and … flamethrowers.

Musk has learned well from the advice. The Boring Company, which aims to build a high-speed transit system in Chicago, among other projects, has been selling hats at $20 each to reach a fundraising goal of $1 million. The hats have already sold over 15,000 despite only being on sale for around a month.

Watch the scene below.

The movie stars John Candy, Rick Moranis, Bill Pullman, and Daphne Zuniga in a parody of Star Wars and other blockbuster ‘80s movies. It wasn’t massively well-received, with a score of 57 percent on Rotten Tomatoes, but it has a devoted cult following. Musk, who also likes referencing Rick and Morty and The Hitchhiker’s Guide to the Galaxy, has a real thing for joke-laden sci-fi works with big fan bases.

It’s not the first time Musk has planted a Spaceballs reference in his projects. Back in 2015, Tesla Model S owners discovered a secret animation related to the “Ludicrous Mode” that enables even faster acceleration. In the movie, this is a speed even faster than light speed.

In the video below, a Tesla Model S P90D owner holds down on the “Ludicrous” button to play a full-screen animation on the central console that mimics the one seen in the movie.

With the advancement of electric vehicle technology, Musk has taken “Ludicrous Mode” one step further. Around the time owners discovered the secret animation, Musk promised that a sequel to the company’s 2008 Roadster vehicle would feature a “Plaid” mode. In the movie, this is one step faster than “Ludicrous.”

Sure enough, Musk delivered. The second-generation Tesla Roadster electric car, unveiled during a special event at the company’s design studio in Hawthorne, California, last month, contains a special Plaid performance mode as seen in the movie. The mode enables the car to reach staggering acceleration times of 0-60 in under two seconds.

Like its predecessor, Plaid features an animation on the central screen similar to the one in the movie.

When the Roadster launches in 2020 with a $200,000 price tag, those who can afford it will be able to live out their Spaceballs dreams and finally reach Plaid.