Statistical characterization of in-car wireless communication channels has recently gained significance, mainly due to the possibility of deploying a wireless sensor network in the vehicle. In this paper, we report different aspects of a statistical analysis of four representative in- car wireless channels based on the received power data collected from a binary phase shift keying (BPSK) transmission experiment. It is shown that the communication channel between the base station and a sensor placed under the engine compartment is the worst in terms of stability, average fade duration, and fade proportion, while the channel between the base station and a sensor placed in the trunk and the channel between the base station and a sensor placed on the hood are the best. We also show that the 4 representative in-car wireless channels can satisfy the maximum packet delay requirement of less than 500 ms and the trunk channel and the in-the-engine-compartment channels can satisfy the requirement of up to 98% packet reception rate. These statistical characteristics of the in- car wireless channels provide important guidelines for the designer of an in-car sensor system.