Options:

F1 - Inf. Money
F2 - Inf. Fuel - fixed
F3 - No Tyre Wear
F4 - Low Tyre Temperature
F5 - Max Car Condition
F6 - Instant Part Design
F7 - Car Part Max Improvement

Notice:

First you must be in manager view where budge appears on screen then activate money cheat and pass a day.
First start a race and once your car start moving activate cheats.
First open part design tab, Select a part like engine and once required time appear to design the part activate Instant Part Design cheat, Close the window then open it again.
First open Parts Improvements Window, Then activate Car Part Max Improvements close window and open it again and all parts will be improved to the ma.