Mickey's Speedway USA Codes -

Quick start:
Immediately press A as the third light turns on during the pre-race countdown.

Negative coins:
Win a gold or platinum on the mirrored Traffic Troubles.

Digital speedometer:
Win a gold or platinum on the mirrored Motorway Mania.

Tiny racers:
Win a gold or platinum on the mirrored Freeway Phobia.

Dewey:
Win a gold in all circuits under the amateur difficulty setting to unlock Dewey.

Louie:
Win a gold in all circuits under the intermediate difficulty setting to unlock Louie.

Rainbow Goo:
Win a gold or platinum in the first three circuits under the amateur difficulty setting.

Heckle button:
Win a gold or platinum in the first three circuits under the amateur and intermediate difficulty settings.

Unlimited retries:
Win a gold or platinum in the first three circuits under the amateur, intermediate, and professional difficulty settings.

Disable boost pads:
Win a gold or platinum in mirror mode on the Victory Vehicles circuit:

Victory Vehicles circuit:
Win the first three circuits under the professional difficulty setting to unlock the Yellowstone, Everglades, Malibu, and Washington, D.C. races.

Frantic Freeway circuit:
Collect all four car parts.