How do driver, kart, and glider levels work?

A driver, kart, or glider's level may increase when you obtain a driver, kart, or glider with the same name from the pipe or use a level-boost ticket. Higher level drivers are more likely to activate Frenzy mode, higher level karts have a higher bonus-point multiplier, and higher level gliders have a longer combo time duration. On favorite courses, a bonus-points boost will be added based on level and base points.
The number of duplicate drivers, karts, or gliders needed to reach the next skill level is as follows:
Skill level 2:
High-End: 1, Super: 1, Normal: 2
Skill level 3:
High-End: 1, Super: 2, Normal: 5
Skill level 4:
High-End: 2, Super: 3, Normal: 8
Skill level 5:
High-End: 2, Super: 4, Normal: 11
Skill level 6:
High-End: 3, Super: 5, Normal: 14
Skill level 7:
High-End: 5, Super: 8, Normal: 20
Skill level 8:
High-End: 8, Super: 16, Normal: 40