San Francisco Rush

Turn Cones into Mines:
For explosive action, quickly press L, R, L, R, L, R on the SETUP screen.
This code turns the cones into mines that blow up anything that hits them.

Turn Tracks Upside-down:
To turn the track upside down, quickly press Up, Right, Down, Left, Down, Right, Up, Left on the SETUP screen.

Foggy Night:
Go to the Options screen and change "Fog" to the Heavy setting.
Then hold all four C buttons and press right on the Control Pad.
You should now have access to Foggy Night.