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.