We investigate how to obtain a balance between privacy and audit requirements in vehicular networks. Challenging the current trend of relying on asymmetric primitives within VANETs, our investigation is a feasibility study of the use of symmetric primitives, resulting in some efficiency improvements of potential value. More specifically, we develop a realistic trust model, and an architecture that supports our solution. In order to ascertain that most users will not find it meaningful to disconnect or disable transponders, we design our solution with several types of user incentives as part of the structure. Examples of resulting features include anonymous toll collection; improved emergency response; and personalized and route-dependent traffic information. Categories and Subject Descriptors C.2.1 [Computer-Communication Networks]: Network Architecture and Design—Wireless communication General Terms Algorithms, Management, Design, Security, Verification Keywords Audit, incentive...