I had just drove the car off the lot. On my way home there is this violent grip of the steering wheel pulling me into oncoming traffic. Then again to the right towards a telephone pole. During another casual drive, there was a loud clunk and another violent grip of the steering wheel to the left towards the yellow line. This has happened numerous times. I explained to the dealer that lane assist is suppose to keep you on the road not pull of you off. Unfortunately this happens randomly so it did not happen when the car went in for service. If I leave lane assist turned off my car is fine however it is a brand new and its a feature I am not able to use. This is my first Buick and I am disappointed.