The Socs are in a violent rivalry with the Greasers, a poor gang of teenagers. The Socs are spoiled children from good families who have everything they want. They are cultured and sophisticated, and have parents who care for them. The Socs have so much time and money that they cause trouble by harassing the Greasers. 
The Socs' cars represent their power and the Greasers' vulnerability. The Socs can afford to buy cars, which gives them increased mobility and protection.