open [gamedir]UserData[PROFILENAME]SRGrandPrix05.cch
with notepad or another editor.
[CAREER]
Experience=0
Money=500
simply edit the values and save the file
Cheat mode:
Select either of the two race car classes the main menu. Then, select "Control" and start a test run on any track. At the debriefing menu, enter ISIBABYFACTORY as a case-sensitive code in the dialog box to the bottom left of the menu. Select "Send" then exit the race. You will now have most cars for the current class unlocked with extra money.