If you are low on cash, just defeat one of the opponents on the black-list. You 
will get two marks to use on several different things. Do not use them on the 
Uniques early in the game. Instead, use them on the middle or the left 'Random' 
choices. They should always come out to either be a big cash bonus or the 
opponent's pink slip.

Because you can repeat blacklist races you have completed and still earn money 
for it, do any of Kaze's tollbooth races. You will get $10,000 for winning. By 
this point in the game you should have hopefully obtained the Porsche Cayenne 
from Baron. If not, your fastest car should do fine.