Gaining a lot of money and all...
	Various Steam Achievements...

In the main menu, pick any of the two race car classes and once you do that, go to Control and start a testing run. Doesn't matter what track you select. In the menu where you actually debrief everything, you'll see a chatbox on the lower left of the menu. In that box, type ISI_BABYFACTORY (All caps) and send it, then exit the race. Once you do, you'll see that you're left with way more money (Around 1-2 billion depending on which class you selected) and most, if not all of the cars, unlocked.

NOTE: You must re-enter this code for each car class if you want to use it for both of them.

Achievement	How to unlock
1 kilometer driven in practice	You've driven 1 kilometer in practice sessions.
10 kilometers driven in practice	You've driven 10 kilometers in practice sessions.
100 kilometers driven in practice	You've driven 100 kilometers in practice sessions.
100 kilometers driven in race	You've driven 100 kilometers in races.
100 km/h in practice	You've reached 100 km/h in a practice session.
1000 kilometers driven in practice	You've driven 1000 kilometers in practice sessions.
1000 kilometers driven in race	You've driven 1000 kilometers in races.
150 km/h in practice	You've reached 150 km/h in a practice session.
200 kilometers driven in practice	You've driven 200 kilometers in practice sessions.
200 km/h in practice	You've reached 200 km/h in a practice session.
2000 kilometers driven in practice	You've driven 2000 kilometers in practice sessions.
2000 kilometers driven in race	You've driven 2000 kilometers in races.
250 km/h in practice	You've reached 250 km/h in a practice session.
300 km/h in practice	You've reached 300 km/h in a practice session.
500 kilometers driven in practice	You've driven 500 kilometers in practice sessions.
500 kilometers driven in race	You've driven 500 kilometers in races.
Behind the wheel	You've sat behind the wheel of a car.
First pitstop in practice	You've made your first pitstop in a practice session.
Racing at Dawn	You're racing at dawn.
Racing at Dusk	You're racing at dusk.
Racing at Midnight	You're racing at midnight.
Racing at Noon	You're racing at noon.
Rolling start from pole position	Your first rolling start from pole position.
Standing start from pole position	Your first standing start from pole position.