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In the original version, every character's vehicle has their own unique color, including Cars. In Diddy Kong Racing DS, every character's vehicles are yellow by default. The player can access Taj's Wishes Menu to purchase upgrades for a Car's speed, handling, and acceleration. They can also customize a Car's paint color from a slider or put an emblem on it, much like in Mario Kart DS.
Cars are usable in every level except Hot Top Volcano, Whale Bay, Pirate Lagoon, and Boulder Canyon, where the player must use a Hovercraft or Plane instead. Cars are usable in Everfrost Peak in the original Nintendo 64 version, but since the course's icy pond is thawed in the DS release, Cars cannot be used in the stage. They are most often the default vehicle for each course that they are ridable in.
The player can select a course's available vehicles to race in from either the "Tracks" menu or by completing a Silver Coin Challenge (or Balloon Touch Challenge in the DS remake). Cars are most often one of the vehicle options.