NS2: how to simulate hosts running two different Mac protocols on the same network?

I want to modify the existing routing protocol and simulate how well it works in a network with two different types of nodes, cars with 802.11p and AP on the side of the road with 802.3.

Does anyone know how to run a simulation of a routing protocol on a network with two different Mac protocols like 802.11p combined with 802.3 ??? Any links I would appreciate ...

Thank.