But you don't need it any more.
Before the 25% completion, there's a rally race that makes you 250K (after selling the car) - I can't remember the race. In any case.... it's quick cash.
You fully eliminate the money problem at 25% by doing the following:
0) Make sure your B-spec driver is up to about 4000-5000 skill points. If you have been running all series twice (and selling duplicate extra car... more cash) it should already be.
1) Go to the Chrysler dealership, buy a (I believe) Crossfire for about 40K - see single-brand race to be sure.
2) Upgrade as little as possible, just enough to win the race.
3) Win the single-brand Chrysler series and win the Viper.
4) Upgrade it fully. Run the 24hr Nurburgring with Viper. Win by 1-2 lap lead, getting a lot of B-spec exp in process, and of course 1.5 mill + F1 car.
5) After winning or if you have trouble winning the 24hr, use the Viper to win (easily) the Toyota Minolta in the 200Mile El Capitan (a or b spec).
6) Use the Minolta to run the 24hr Nurburgring multiple times... and sell any F1 duplicates you don't want to keep. Bye bye cash problem.
7) Be smart and make an excess 8-10 million that you won't touch until day 694-700. On those days go to the used car lot and buy the famous 4 black cars (see other threads or FAQs). You are now the golden child.