Service discovery is an essential component for applications in vehicular communication systems. While there have been numerous service discovery protocols dedicated to a local network, mobile ad-hoc networks and the Internet, in vehicular communication systems, applications pose additional requirements; They need to discover services according to geo- graphical position. In this paper, we propose a location-aware service discovery mechanism for Vehicular Ad-hoc NETwork (VANET). The proposed mechanism exploits IPv6 multicast on top of IPv6 GeoNetworking specified by the GeoNet project. Thanks to the GeoBroadcast mechanism, it efficiently propagates service discovery messages to a subset of nodes inside a relevant geographical area with encapsulating IPv6 multicast packets. We implemented the mechanism using CarGeo6, an open source implementation of IPv6 GeoNetworking. Our real field evaluation shows the system can discover services with low latency and low bandwidth usage in VANETs.