Easy Formula 1 Car
Once you get 25.0% game completion, get the Nissan Motul Pitwork Z from the Japanese GT championship (The longer one.) Once you get that car, give it the Stage 4 Turbo tuning. Also, don't forget to give it super hard racing tires. Ok, now for the boring part. Get in that car and go to Endurance races. Do the Nurburging 24H race. Your car should be better than all of theirs so just do B-Spec. Put the driver on 3 (Steady Pace) and Overtake. Leave your console on for the duration of the race. Your car should go in the pits by itself every 4 laps. If you can, monitor the race so you can click X3 view speed every time the car gets out of the pits. I am currently on lap 201 and have 3 Hours left (I think).

Easy Money
For easy money go to Japan events on the left on the menu. Then go it to japan championship this event is easy with the right car to save yourself some time get a car and tune it up i used the (2004 Amuse CarbonrR r34)use b-spec racing (you can race the events nomaly if you want) let the car run on the steady speed (number 3)and put overtake on by hitting traingle and turn the race speed to 3x by holding L1 And hit the left button two times. The sit back and wait. Race the event and win get 7,500 credits a race, 35,000 when you win the champioship. You win a Car a nissan 350z concept car which you can sell for 318,000 credits. this can take just under a half hour and you make about 400,000 credits. not bad huh.

Hidden Controls
There are a number of "hidden" controls in Gran Turismo 4 that will make navigating the game a bit easier.

On the main Gran Turismo Mode screen, press L1 to jump the cursor to Home, and press R1 to jump the cursor to the country of your vehicle's manufacturer.

When looking at your garage in Home, press START to bring up the vehicle settings screen.

When changing your vehicle's settings, press START to enlarge the Engine Power/Torque curve.

At the end of a series race, press START to skip the finish times and championship points screens.

During a replay, press L3 to fast-forward.

During a pit stop, press X to to stop refueling, letting you get out of the stop faster.

With the Driving Force Pro wheel, press any combination of the LEFT, RIGHT, and DOWN buttons on the D-pad to look in that direction while driving.

Secret Black Cars
The vehicle line-up in the used car showrooms is constantly changing. On the last week of the changing cycle--starting day 694--four secret black race cars appear in the showrooms. Two of the cars are in the Used Car Showroom I and the other two are in Showroom II, and they only appear for one week (Gran Turismo time). All four cars can be purchased for about Cr.8,500,000 total, which is an absolute bargain for these sort of race cars.

2022 Nike One Morse Code
If you look really close on the side of the Nike One, you can see a small area near the front of the car of morse code. If you go into photo mode, this will become clearer. The morse code is written backwards as to be seen correctly from inside the car.