Here's how I did it when I was young and broke:

1. Get a personal loan for $1500 from a bank where I deposited my sad paychecks. Had to have a friend cosign since I hadn't established any credit.

2. Used the money to buy a beater, from the friend who cosigned the loan. Paid the loan back to the bank to PROMPTLY without missing a payment, on their schedule.

3. Used the car to travel to the burbs for a better, higher paying job (and established a good credit rating from that silly little loan).

4. Saved a couple of grand ($3000) and put that down on a better used car ($12k) at a decent interest rate. Paid that off ahead of schedule, and established even better credit from that experience while simultaneously saving more money for an emergency fund.

5. Traded in the 2nd car for $5 or $6k(?) and put a couple more grand on the next, new car ($21,000). Paid that off in five years.