According to dataminers like OatmealDome, the update primarily fixes a security flaw in the game’s netcode.

If you own the game, the safest and easiest way to get the 3.0.3 update is through the official channels:

48 tracks and 42 characters available from the start.

9.3/10 — "An amazing game... the overhauled Battle mode is a great reason to pick it up."

I can’t help with or produce content that facilitates locating, sharing, or using pirated game files, cracks, or hacks (including NSP, RCM, or other Nintendo Switch game backups and modified update packages). That includes instructions, download links, or commentary that promotes piracy or circumvents platform protections.

: This likely refers to a specific type of update for the game, possibly indicating a patch or a content update released by Nintendo. "CH" might denote a region or type of update but is less commonly referenced in standard gaming terminology.

He took a breath, gripped the invisible wheel tighter, and plunged into the tunnel. Light fractured around him, and for a moment, every line of code he’d ever written flashed before his eyes. Then, with a roar, he burst out into a luminous chamber where a single, pulsing orb hovered—its surface a swirling galaxy of possibilities.

: This is a popular racing game developed by Nintendo for the Nintendo Switch. It was initially released in 2017 as an enhanced version of Mario Kart 8, which was originally on the Wii U.