Vehicular ad hoc networks present challenging characteristics, such as very dynamic behavior and sparse connectivity, that need to be taken into account in designing adequate communication support. Gossip-based protocols have recently emerged as an effective approach to providing reliable and efficient communication in this domain. Nonetheless, despite the preliminary encouraging results, to the best of our knowledge, no previous work has systematically analyzed how gossip protocols are affected by the intrinsic characteristics of vehicular networks such as the very specific mobility patterns of vehicles, the relative abundance of memory and computational resources that vehicles offer, and the availability of geographical information through GPS receivers. In this paper, we aim at filling this gap by examining core requirements of vehicular network applications and analyzing the research challenges that gossip-based communication protocols need to address.