According to dataminers, the primary focus of this update was a within the netcode. Unlike previous major updates (such as Version 3.0.0), this patch did not introduce new characters, tracks, or balance changes to vehicle statistics. Its purpose was purely technical refinement to maintain the game’s longevity. Best Builds Post-Update 3.0.3

Improved performance for online lobbies to prevent disconnects.

: A dedicated button on the main menu to listen to all game tracks. Mii Racing Suits : Several new outfits, including a Pikmin Suit unlocked via amiibo.

These builds offer higher raw speed , allowing players to pull away on straightaways, though they require more precise drifting to maintain momentum. How to Update Your Game

: Currently widely considered the most versatile "best" build due to its high Mini-Turbo and acceleration stats. Inkstriker

To keep your game running at its best, make sure to check for updates manually if your Switch doesn't do so automatically. Simply press the + button on the game icon on your Home Menu and select . If you'd like to dive deeper into the stats, I can:

“Mario Kart 8 Deluxe update 3.0.3 – NSP (Nintendo Switch ROM/update file) – best version.”