Credit Cheat:

Make a backup of the Carma.pak file in the assets
folder. Then open the file in wordpad. Scroll down
to the part that starts: 

ENDDIFFICULTY
Here you will find the attributes for
Ped_Credits / Checkpoint_credits and the
like ...add a few zeros to the numbers and
remove the line
APO_TRADE_OFFENSIVE
that is at the bottom of this part of the text or
else the hack won't work. This hack will
make it nice and easy to score credits and
afford all the cars.