Add some preload and that will be sorted. Some default sets aren't ideal but that's what setups are for to suit your style. Once you tune out some of the oversteer the car is very quick compared to the others, then eventually you will need some of that oversteer back to use as a tool.
Lift off is specially one thing to avoid if you're not straight. And if you had to and get oversteer the best reaction is to re-accelerate, you don't even have to countersteer. Use the right foot, it's pretty magical when you're used to it.
(I know "normal" street car that behave like this, there's nothing wrong here )
You can tone down the oversteer a bit with setups but it will always stay.
The only way to fix this behavior is your driving style. Stay on the gas a little while braking into corners and release the brake slowly. And do what Le poilu said
Don't we already have a thread about how to drive the FWD WTCC's?