Find the three hidden stars located in This Ol' House GP in single player mode.They are located behind the jack-in-the-box close to the start; in a bon-bon located on the wooden planks above where is possible to see the man taking a bath down below; and in a pipe that is located directly after the big spider -- the star should be to the right once you go through the pipe.
Find the three hidden stars located in Perilous Places GP in single player mode. They are located behind the grenade immediately after the moving piston; in a lava rock along the lava path; and at the three quarters point of the lap, after going up a hill where there red barrels are around, go to the left and the star should be quite visible.
Find the three hidden stars located in Hoedown GP in single player mode. They are located in the first party popper after going up the convey belt; underneath the tapping foot of the woman with hairy legs; and at the end of driving the hay bails road drop down slowly and land on another hay bail -- below that has another star on it.
Find the three hidden stars located in Jungle Jamboree GP in single player mode. They are located behind the first jump; after passing the first check point do a 90 degree left turn and go in the square hole that is covered in fire (a short cut), and after going through the short cut go ahead a bit more; and the last one should be visible behind a broken statue head laying on the ground -- you might need to jump in order to get the star.
Find the three hidden stars located in Graveyard GP in single player mode. They are located behind a rock just before the bridge with the skeleton of the man with the weird glasses; destroy the sail on the coffin path next to the sign "Bob Fat and Bald 1802 - 1852"; and in a secret shortcut located right of the fast forward power-up after the man in the jail cell.
Win the Platinum Cup in challenge mode to unlock the Hovercar.
Find the three hidden stars located in 911: Emergency GP in single player mode. They are located at the first sewerage drain to the right at the start; among the group of boxes close to the start; and behind a wall after going down a flight of stairs.
Find the three hidden stars located in Beachside GP in single player mode. They are located to the left outside of the submarine helmet; behind the sand castle before the beach ball; and underneath the first jump at the very beginning.
Find the three hidden stars located in Toy Town Sci Fi GP in single player mode. After the first teleport go left, there should be one located on underneath a pipe and next to a cup; after going through the first teleport, another star is located to the right on a arm of a chair; and a star is located behind a pillar to the right of the speed up the has the freeze and pause power-ups.
While turning a corner, hold L3 for a sharper turn.