In the past decade automobiles have evolved from mechanical devices into very complex electro-mechanical systems. With the increasing number of ECUs comes the complexity of connecting them to have a meaningful interaction with the rest of the system. In this scenario there is no one size fits all approach. ECUs have different communication requirements based on bandwidth, reliability, speed and security. Infotainment ECUs need high bandwidth to stream the audio and video content but can be tolerant to frame drops and latency. Engine Control ECUs need less bandwidth but must have high reliability. Hence, when it comes to In-Vehicle network a variety of networks co-exist such as Ethernet, CAN and MOST serving various purposes. This paper attempts to make a case to add low power wireless network to the mix to optimize the space and cost factor and looks at applications that are appropriate for such networks.Today’s automobiles have a plethora of sensors and actuators often connected to the nearest ECU over point to point connections. Making these tiny sensors and actuators wireless greatly simplifies the vehicle network architecture and takes the load off the CAN bus to handle critical messages. This paper discusses the communication network, components and describes modular wireless vehicle sensor network architecture with focus on security, reliability, openness and usability. The proposed architecture uses proven and industry standard protocols such as 6LoWPAN and MQTT to define the modular in-vehicle wireless sensor network.