We consider a cooperative environment in wireless mobile networks where information is exchanged among nodes in a peer-to-peer fashion. We apply a pure peer-to-peer approach (i.e., without the intervention of servers) and we seek to devise an efficient query/response propagation algorithm. Our approach, called Eureka, identifies the regions of the network where the required information is more likely to be stored and steers the queries toward those regions. To discriminate among regions, we introduce the concept of information density and a procedure that allows nodes its estimation. The effectiveness of our scheme is evaluated through simulation in a vehicular environment with realistic mobility models.