aerodynamic efficiency

im doing an a-level project at school and need some serious advice and pictures, naturally, u guys come first!

i need info on;
1. aerodynamic drag properties of popular cars
2. info on sources for aerodynamic trays (underneath a car)
3. i need good pictures of the underside of popular cars

i also need the recognition of an engineering company for my assesment , so i you run a firm can u guys pm me, preferrably british, and ill tell u more about what i need you to do, thanks a lot