Squeaky Clean Sprint

Squeaky Clean Sprint is a course featured in Wave 5 of the Booster Course Pass for Mario Kart 8 Deluxe. The course is set in a giant bathroom, similarly to how 's Mario Kart 8 appearance is set in a giant bedroom.

Assets for the course can be found in the files of Mario Kart Tour, being assigned the course's internal abbreviation of "Mobbr". The "mob" opening indicates the course was developed as a new course for Mario Kart Tour, identically to Sky-High Sundae and Yoshi's Island. The assets in question include "JumpMobbr" and "JumpStickyMobbr".

References to the Super Mario franchise
Similarly to the Mario Kart 8 version of, the course contains a number of small references to various games from the Super Mario franchise in the background of the course:
 * A clock resembling a Biddybud (and by extension a Biddybuggy) appears near the starting line.
 * A can of Princess Orange can be seen near the bathtub segment.
 * Stars pattern the bath curtains.
 * The wallpaper of the bathroom, seen most clearly around the bathtub, features the cloud sprite from Super Mario Bros.. The color, too, makes the wallpaper resemble the sky from World 1-1.
 * Lakitu's Cloud can be seen on several balloons.
 * Sunglasses resembling those Princess Peach wears while visiting the Lake Kingdom in Super Mario Odyssey can be seen leaning on top of a suitcase.
 * The aforementioned suitcase has a number of stickers plastered on its side, one of which depicts a Shine Sprite.