Each Kart can be leveled up. Leveling up a Kart Racer improves their attached Skill to make them an overall better racer. To level up your Kart, you will need Kart Tokens and some Slime Coins for the Kart you would like to UPGRADE.
Skills are special abilities that affect the performance of a Kart. A Skill may be attached to both a Kart and a Part. Bonuses of a Skill will grow when either the Kart or Part the Skill is attached to is upgraded.
You can Modify your Karts by equipping Parts. Each Kart comes with three customizable slots that can add additional Skills to your Karts: Tires, Engines, and Exhausts. Parts can be won in races or obtained in the Shop.
Additionally, individual Parts can be leveled up to make their Skills even stronger. Parts can be leveled up by collecting more of the same Part and some Slime Coins.