When driving 40-70 mph and hitting any road irregularities (offsets in pavement at bridges, old to new pavement, man hole covers, road patches) the vehicle back end skips sideways with a loss of control. the vehicle will start to head into the next lane and needs to be steered in the opposite direction to correct it. we do not feel safe driving it. others in the car have said they have never experienced anything like it. dealership is telling us this is normal. vehicle is under warranty and we can't get resolution to this. *tr