ODE vehicles

Sorry I musn't have explained properly... The example vehicles that come with ODE, they have rotating wheels and suspension and stuff and they all fit in with the physics system. I was wondering how I have to name my objects and whether I have to animate them or not and if so how does it need to be done. Also what exporter to use.

I'm not sure I understand your question, but the example vehicles are just put together using the basic geoms and joints. There isn't any kind of special model format for ODE that automatically loads that information from a file.

You don't necessarily create a model for ODE that exactly corresponds to the visible OGRE model. Generally what you'll do is create simplified ODE objects for simulating the physics (e.g. a car would have 4 cylinders for the wheels and a box for the body, with joints connecting them). Then you write some glue code that updates the position & orientation of the corresponding Ogre entities every frame. You may want to check out the code for OgreODE for an example (not sure if it's up to date but it should give you an idea of what's involved).

There is an xode file format that can describe an ODE scene but it's not much like a model format.