I do not think you need it, because there are many protocols and mobility models implemented already. Working with IEEE 802.11p is similar to IEEE 802.11a, I guess you know the relationship between the two protocols? They are all for vehicular networks. I will also advice you to install INEMANET, SUMO, they will all help with vehicular networks. I am working on IEEE 802.11p as well. If you do no find 802.11p, you can use 802.11a, but you can define this new standard, if you do not have it, because i did that in INETMANET for 802..1p.
Protocols and mobility models you need for vehicular networks are already implemented, except you need something different or new. Hope this help!