In the last few years we have witnessed an increasing number of cars being connected to the Internet. All indicators suggest that this trend will continue, and vehicles will soon become first class citizens on the Internet. Vehicle networking opens the door to a vast new class of applications ranging from car monitoring and diagnosis to passenger assistance, communication, and entertainment. In this article we present a comprehensive survey of the existing mobility support solutions, and discuss various design trade-offs and remaining issues in view of vehicle networking. We hope that these discussions can provide useful inputs to car manufacturers in their design considerations for bringing all cars online.