Mario Kart 8 Deluxe placeholder music files have been discovered after the latest update that could be hinting at future Booster Course Pass DLC tracks.

The “prefetch” files were discovered by YouTuber’s log reader, but BL posted the findings on YouTube, via VGC, and they appear to correspond to music tracks from classic Mario Kart games.

The 50-second video contains each of the 15 discovered music files, but only the first few seconds of each track are played. This is because “presearch” files are designed to quickly start the music until the entire song is playing in the background. It seems that the YouTuber was also able to identify each of the songs in his classic Mario Kart circuits. The list of courses can be found below and could arrive in future waves of DLC Booster Course Pass:

• London Circuit (Mario Kart Tour)
• Peach Gardens (DS)
• Boo Lake/ Broken Pier (GBA)
• Rock Rock Mountain (3DS)
• Berlin Byways (Mario Kart Tour)
• Waluigi Stadium/ Wario Coliseum (Game Cube)
• happy mountain
• Rainbow Road (3DS)
• Amsterdam Drift (Mario Kart Tour)
• Singapore Circuit (Mario Kart Tour)
• Los Angeles Laps (Mario Kart Tour)
• Sunset Wilds (GBA)
• Bangkok Rush (Mario Kart Tour)
• Vancouver Speed ​​(Mario Kart Tour)
• Maple Tree Path (Wii)

The Booster Course DLC was announced earlier this year and will consist of 48 courses. Wave one was released shortly after, on March 18, and included the first eight tracks. Wave two launched on August 4 and features eight courses, including an all-new circuit called Sky-High Sundae. The Booster Course DLC is $25 on its own. Also included with Nintendo Switch Online + Expansion Pass at no additional cost.

Elsewhere, Mario Kart 9 is rumored to be in the works and will include a “new twist.” According to Kantan Games consultant Dr. Serkan Toto, the game is currently “in active development” and Nintendo could introduce the new title this year.