Do you know what GP3 really needs?

[Silent.B.Deadly]

A handbrake :)

but seriously, how does anyone control these cars without the driving assists on?

I just tried to race in australia with all the assists off and explored all the gravel traps for less than half a lap before the engine blew.

Steering wheel and pedals have just become a priority.

[Reality]

What are you using as a controller?

If its a keyboard then put the throttle assist on. Its near impossible without and you wont match the speeds of the other cars in ACE mode. So make sure its on.

Other than that, if you are using a joystick/wheel then alter the settings in the controller setup so you are happy with them.

Finally play around with the Car Setups. Some of the default track setups are just nasty. Alter them until you find a setup that suits you. Also read the advanced car setups in the manual. This really helps with the handling of the car.

Then drive lots and lots until you know the circuit with your eyes closed :)