Cars and Automotive Design

I need advice on how to design car parts not the surface modelling.

I have to do a design project for a course. I need to design a car using gear mechanism and shaft, basically the skeleton of a car with the suspension as well. Now I am stucked at the design of steering wheel. And some of the mates aren't working properly. I think it's because of the sizes and teeth number of the gears. Can anyone help me by giving any material related to the design of car parts? or any help would be appreciated. Thanks,