This cheat is recommended for intermidiate level computer users only. If you don't know what the cheat is talking about don't try it.
Find a car you want, but cant afford. Now, leave the game. Find the name of the car you want and .txt, so if you wanted an Escort, you would find Escort.txt. Now use a text editor (I use TXED) and find a number (at the beginning). It should look something like 00000012345. Now, replace the places where the 12345 # is and put 0s in there place. Now just leave a trailing 1. Now the car will cost all of $10. This is not only a way to get the car you want, but makes it cheaper to just buy a new car each time instead of refueling/fixing dammage.