Test Drive 2: The Duel (SNES)

Custom cars:
Start a new game and begin a race. Hold L + R on controller two before the cars begin to move to display the customize car screen. Use controller two to adjust the various options that include autoshift, car height, drag coefficient, acceleration coefficient, maximum G-force, or scrub rate. Additionally, press A on controller two to jump over traffic if enough speed has been accumulated.

Turbo:
Press A on controller two.