We finished our project! The final features include some physics: Our Vehicle can jump, it accelerates according to the actual fall, and steering isn’t possible if both front wheels leave the ground. Unfortunately we did not have time to refactor the code so there are some mistakes in it but overall it is relatively good. Anyway our teacher was very impressed! 
Download the source. It includes very much useful comments so that one can learn from it. The following is covered:
- Generating a terrain from a gray scale height map (bitmap) (including speed optimisation using graphic card buffers)
- Vertices
- Indices
- Normals
- Buffers
- Applying different textures for specific heights. Blending between these textures (includes shader programming)
- Showing more detailed textures close-by and less detailed in the distance (includes shader programming)
- Matrices and quaternions to rotate our vehicle and the camera
- 3D collision detection and handling
- Plane – ray intersection
- Keyboard and mouse input
- Loading 3D models
- Basic physics
Also have a look at these posts:
http://blog.goltergaul.de/2009/10/xna-directx-c-game-project-camera-class-and-first-terrain/
http://blog.goltergaul.de/2009/10/xna-directx-c-game-project-%e2%80%93-depth-details/
http://blog.goltergaul.de/2009/10/xna-directx-c-game-project-basic-collsion-detection/
Studying MultimediaTechnology in Salzburg, Austria 