Vehicular Ad-hoc Networks (VANETs) have emerged as a promising approach to support communications between autonomous cars and the accompanying intelligent transportation systems. Research in this area, namely vehicle-to-everything (V2X) communication, is focusing on two types of technologies: dedicated-short-range communication (DSRC) and advances in cellular networks. However, both technologies have limitations in performance, especially in high-density vehicular scenarios. In this paper, we propose a cognitive protocol translator capable of translating between LTE Sidelink device-to-device (D2D) and IEEE 802.11p DSRC packets, allowing interoperability of the two technologies. We propose this hybrid architecture as a potential solution to address the challenge of interoperability. We demonstrate through simulations the feasibility of our solution and show how the protocol converter has no adverse affect on packet delivery performance of the component DSRC and LTE ProSe technologies.