Gran Turismo
Hidden Video of the GT Staff
In Arcade Mode, first get the hidden tracks, then, on every track, take 1st place with any car in A,B, and C class mode on Normal setting or higher. Then go to Bonus Items, you'll see "Staff Video" on the menu.
Hi-Fi Mode, Bonus Cars and Bonus Tracks
To get all the bonus items in Arcade mode, which include the four other tracks (Autumn Ring, Deep Forest, SSR5, and Grand Valley Speedway), all the other cars (Toyota, Subaru, Dodge, and TVR), the ending movie, and Hi-res GT Mode, you have to beat every single track with each type of car (A, B, and C) under all three modes of difficulty (Easy, Normal, Difficult.)
Free Parts
It seems there is a bug in GT which means you can make free duplicate copies of any parts you buy for a particular type of car. Try this:
Buy two identical cars. Give them a different color scheme if you like.
Buy loads of parts for the first one - fully spec it up if you like.
Check out its list of fitted parts from the garage (you should see a list of what you just bought.)
Switch to the other car and get in it (the one which you haven't fitted any parts on yet) and check its fitted parts list (should be empty).
Still in the second car, go race (Spot Race will do).
When you get options to qualify, go to Machine Setting, then Change Parts. You'll now find you can select all the parts from the other car, tyres, turbos, suspension, intercooler etc, in effect fully spec'ing up the second car.
Exit the race, and go back to the garage. Check out the list of fitted parts for both cars. The parts are now installed for both of them!
NOTE:This won't work for the Weight Reduction or Racing Mod options and a few other things (like port polishing), as these are not available from the Change Parts menu - they're not really "parts" as such anyway. Also, it doesn't seem to work with cars that have been won.
Of course the best thing you can do with this is sell the extra cars. As it cost you nothing to increase its specs, you'll make a profit when you sell it!
Faster Acceleration
To accelerate faster, rev your engine during the countdown. Be sure to go from the lowest point in neutral to the hightest point in neutral, and back down to the lowest point in neutral as many times as you can before you go.
Easy Money
The easiest way to get lots of money later in the game is to race the qualifier for the all nighter. You get $20,000 just for qualifing and it is very easy to do this with the GTO special edition or any other car with good speed/acceleration and handling. It takes app. 1'45" to complete with the GTO special edition.
Concept Car
In order to get the Dodge Concept Car, which you cant buy, you have to win the British vs US race.
Get some speed
Then smash a wall at a 90 degree angle
Hug the wall for about half a lap
As soon as you do that get off the wall quickly and start driving on the road. Enjoy your speed!
Breaking the Sound Barrier
This cheat lets you get up to very high speeds and "breaking the sound barrier". Here are the steps:
1.000.000 $
Go backwards on high speed ring for three laps if you don't go off the track or hit any cars when you pass the finish line the third time you should here a car
horn then at the main menu, you will have 1000000 dollars and the concept car.
Super Car
Super car get a gto twin turbo (mitsubishi) sup it up all the way and it should be able to hit 248 mph.
Super Car (modified)
Originally, Shannon put that if you just 'sup' up a Mitsubishi GTO Twin Turbo, you'll hit 248 MPH. If you know how, mess with the Gear ratio's for the car's racing transmission. You'll be able to hit over 250.
Unlimited Money and all Cars
Enter the Gran Turismo mode. Go into your garage and get into a Dodge Viper R/10 in the blue colour. (you can get this car at Chrisler) go and start the Sunday Cup you will need a B-Licence for this. When you are Racing do the first lap without coming of the Track as soon as you did the first lap turn around and drive the other direction.
Do that one lap without comming of the track once. After you done that pause the game and press L1+R1+cross+up+down and then quit the race. Go to the garage and change your car to anything you like.
If you done this right you should hear a ringing sound under neath your screen it should say "unlimited credits". You will have unlimited credits and all the cars in the gran turismo mode.
Quick cash
Once you have obtained the I-B license, buy a decent car with under 394 HP (I used a tuned up Mitsubishi Lancer GSR VI). Once you have done this, go to the 80's Sports Car Cup, under Special Events. Go to the fifth race in this cup (Tahiti Road). Tahiti road is an easy track to win at, and every time you win, you recieve 10000 cash and a Nissan Skyline worth 125,000 credits. You may not want to sell it though. It has 555 HP and a Maz Speed of 190 MPH. Consider winning this race multiple times, and selling all of the cars but one.