In recent years more and more studies are focused on trust management of vehicle ad-hoc networks (VANETs). However, little attention has been given to the issue of location privacy of the existing trust methodologies in the literature. Although traffic safety remains to be the most crucial issue in VANETs, location privacy can be just as important for drivers, and neither of them can be ignored. In this paper, we propose a trust scheme which aims to thwart internal attackers in privacy enhanced VANETS. In the proposed scheme a secure broadcast authentication protocol and beacon-based trust management system are being employed to maintain the trustworthiness of vehicles. We adopt Dempster-Shafer Theory to incorporate trustworthiness of event message with vehicle trustworthiness from multiple vehicles. In order to ensure the reliability of the proposed scheme, we evaluate the performance under alteration and denial-of-service attack models. The simulation results show that the proposed system is highly resilient to adversary attacks no matter whether it is under fixed silent period (FSP) scheme or random silent period (RSP) location privacy enhancement scheme.