Computer Aided Engineering (CAE) FEA Case Study: Meshing
Creating good quality (parabolic tetrahedral) FEA meshes and material properties 
Tyre: The contact volume (in blue above) was given a Modulus of 100MPa (0.1GPa) and a Poisson's Ratio of 0.49 to simulate flexible rubber. The side wall (cyan) of the tyre were given a Modulus of 10GPa and a Poisson's Ratio of 0.49. This was to simulate a stiffer side wall given by a radial tyre. The Moduli for the tyre were guestimates.
A radial tyre is a very complex composite part - exhibiting all three non-linear characteristics - material, geometric and moving boundary conditions. A non-linear analysis could be performed on the tyre to evaluate it's stiffness characteristics and then a linear static approximation could be derived and used to simplfy the model.
Wheel: Modulus of 70GPa and a Poission's Ratio of 0.33 to simulate cast alloy material - probably LM9. A pseudo hub and suspension were modelled using Rigid Elements (gold/yellow) and a Spring Element (red). The Spring element was programmed as a linear translational spring with a spring rate of 100Kg/cm. The FEA model is a hybrid of geometry and FEA based entities. Pseudo geometry is useful when real geometry does not exist or too complex.