When you're done repairing your first vehicle, bring up the shop websites and buy as many items as you can until you run out of money.
If you're on higher levels, go to the auction house and bid every few seconds just before the timer runs out. This will make the AI bid higher every time and stop bidding when the car's price is higher than your money. Bid as soon as possible this time so you can actually get the car. After that, you're broke gg.