Cseils already said that it spins on-power so it isn't a lift-off oversteer issue.

Mid-corner on-power spinning is often because of something mechanical happening at full roll. Something like the body catching on the ground or the front drivetrain binding up is a possibility. Very tight diffs can cause this too. If there is a large amount of droop as he mentions, it may also be worth trying to limit it, sometimes you can end up with too little load on the inside tyres and it gives up grip late in the corner. I would generally try stiffening a car up that is unstable at speed.