It's a hard goal for the car industry in US to sell more than 17 million cars and light trucks year. Buyer demand will become sated at one point. Of course there will come the moment when manufacturers will be forced to offer less attractive deals in order to keep the customer interested, but even this strategy can't work forever. Thus, sales would begin to drop from their recent peak, which will create a set of difficult challenges for car companies that operate in the United States. A forecast for January sales predicts a dip of 3% to 1.13 million, which translates into 31,000 vehicles. Some car companies will start to be part of trends that may erode their earnings.Specialists predict the drop will be extremely uneven among manufacturers. Volkswagen, which also owns the Audi and Porsche brands, will begin to rebound sharply from a sales collapse brought on by a diesel engine cheating scandal.