The Shop in Mario Kart Tour is where you'll acquire new Drivers, Karts, Gliders, and various upgrade tickets. The 'Daily Selects' section refreshes every 24 hours and offers a rotating selection of common and super rare items for purchase using Coins. This is your primary source for acquiring specific items without relying on the gacha-style Pipe. Always check the Daily Selects for items you need to level up your existing D/K/G or to fill gaps in your coverage. The 'Pipe' section is where you spend Rubies to pull for new and rare items. Each pipe has a specific set of spotlight items with increased drop rates, so it's wise to save your Rubies for pipes that feature items you particularly want or need for ranked cups. Additionally, the 'Tier Shop' (unlocked later) offers exclusive items for purchase with Tier Shop Tokens.
