Anarchy: Rush Hour

You start the game with one car that is given to you: The "Rampage". That car does NOT count. You need to participate in a few events to gather some in-game cash. Then go to the "Garage" and scroll right to the 3rd option: "Car Dealer". Hit to enter the "Car Dealer", then choose a car from the list that you can afford and hit to purchase it.

If you were to buy the very first and cheapest car on the list, that would be the "Trinity" and it can be yours for $37,000. The game starts you off with $50,000.