Connected vehicles are designed to make informed safety-related decisions based on data/information they receive from various on-board sensors and other vehicles in the vicinity. However, attacks directed towards on-board sensors and network attacks on the wireless communication channels can adversely impact the correctness and integrity of this information and present a grave security and safety challenge to connected vehicles. Current centralized security solutions are not a good fit as they do not scale well and are unable to validate the correctness of the shared data. Decentralizing security provisioning in connected vehicles by means of the upcoming blockchain technology is an interesting alternative for overcoming these limitations. However, current permission-less linear hash-chain based blockchain solutions have low transaction throughput, high computational cost and are resource intensive, thereby making their adoption for designing a security solution for resource constrained connected cars difficult. In this paper, we present TangleCV, a decentralized technique for secure message sharing and recording for connected vehicles using an approach like Tangle, a directed acyclic graph based blockchain architecture. We introduce an initial design of TangleCV and describe how it provides improved efficiency and scalability against information correctness and information integrity attacks in connected vehicle networks.