Jump:
On the northeast side of the river there's a big circle. On the north side of the circle ther's a wooden door, jam it and you'll go in a tunel. Go fast. When you get out on the other side go straight and into the glass.When you get in the building there's a place you can turn to your right and jump.:)

Big Air to Free Car:
In New York go to the big park and face opposite way. go full speed up the ramp in the building in middle of street. go to the left and the red circle will be on the roof.

Unlock All Cars:
up,up,down,sqaure,triangle,circle

Use Dune Buggy from Smuggler's Run:
Insert a memory card with a saved game from Smuggler's Run to use the Dune Buggy from that game.

Manhattan police:
Successfully complete Manhattan level 10 in Head-2-Head mode.

London police:
Successfully complete London level 10 in Head-2-Head mode.

All Cruseros:
Successfully complete Manhattan levels 1, 4, and 7 in Head-2-Head mode.

All Jones:
Successfully complete Manhattan levels 2, 5, and 8 in Head-2-Head mode.

All Piranha:
Successfully complete Manhattan levels 3, 6, and 9 in Head-2-Head mode.

All PTs:
Win the 1st, 4th, and 7th Head-2-Head races.

All Modicums:
Win the 3rd, 6th, and 9th Head-2-Head races.

All Ascents:
Win the 2nd, 5th, and 8th Head-2-Head races.

Manhattan bonus cars:
Win the 12th, 13th, and 14th waypoint races in London in arcade mode.

London bonus cars:
Win the 12th, 13th, and 14th waypoint races in New York in arcade mode.

Bonus cars:
Look for red dots that appear on various levels. Place your car on the dot until a gurgling sound is heard to unlock a new car. Some of the dots can be found at the following locations:

London:
Go near the center of the map. The dot is inside the Parliament building (block building with pillars on the outside). Drive through the window to get inside.

Find the reddish building with advertisements and an animated screen on it. Also, there is a box that almost looks like a padded cell in the middle of the street near it. Find the ramp leading up along the side of the building. Before you exit the ramp, you should be going approximately 30 to 45 mph (depending on the weight of your car). After hitting the roof immediately slam on the brakes. The dot should be to the right of you.

Find the strange turn near the Parliament building. Climb up a ramp, then jump to the left or the right, but do not fall off. Turn around to find the dot.

Once you start in London, make a 180 degree turn and head towards the blue blinking "Speed" sign. Go into the ramp at full speed. Go over on to the next roof and hit the brakes. Then, make a left turn and you will see the dot.

New York:
Go near the park above the big tunnel. The dot is on top of a roof that you need to jump to reach.

Go near the aircraft carrier. The dot is inside the second story of a building that you need to jump to enter.

How to get on the ship:
In New York, there is a blue spot on one of the edges of the map. Go on the curve road and drive at around 100mph. Look for the blue spot, there will be a hole in a building and that's where you have to go through to get on the ship.

Get Nitrous Boosts:
In order to geed the Nitrous boosts, you have to get the third level of a car. Once you have the third level car, for instance the Last Truck, go into a race. Then, click the horn button. You should hear a WHOOSH. (You get a limited supply, so use it wisely; around 5) This really will help you break those neck-and-neck races on the straightaways.