You might be able to find some pointers from the following publication,
which seems to be concerned with this problem and is using OMNeT++
(together with Veins) to achieve this goal:
David Eckhoff, Mykola Protsenko and Reinhard German, "Towards an Open
Source Location Privacy Evaluation Framework for Vehicular Networks,"
Proceedings of 80th IEEE Vehicular Technology Conference Fall (VTC
2014-Fall), Vancouver, BC, Canada, September 2014.
http://www7.informatik.uni-erlangen.de/~eckhoff/publications/inc/eckhoff2014toward-abstract.shtml
Best,
Christoph