Operating an engine upside down causes oil starvation. Blue exhaust smoke will occur from oil submerging the cylinders, and the engine bearings could fail.
If a vehicle starts fishtailing from side to side, you need to countersteer earlier and faster. Using a steering wheel (or gamepad) is highly recommended.
When cornering with a keyboard, repeatedly tap [action=steer_left] or [action=steer_right] to better control the steering angle and prevent unwanted understeer.
Cars with more weight on the rear wheels can have a tendency to initially understeer with throttle application, and then oversteer suddenly. This is called "snap" oversteer.
