Step 3: Add Details
Model the wheels (add a circle and extrude), tires, suspension and engine.
There are a lot of nuts and bolts in this model, which can be added using the Bolt Factory addon (File > User Preferences > Addons > Addmesh Bolt Factory).
Model the seat, front and rear headlight (start from a plane mesh with Mirror and Subsurf enabled).
Add the cables and a border of aluminum using bezier curves and enable Bevel (set Fill to full). The more details we are able to add, the more realistic the result will be.
Step 4: Material Setup
We will use the Cycles render engine for this project.
The scooter paint is a mix of a diffuse and glossy shader, both mixed with a glossy. The wheels and metal details are glossy materials with different level of roughness. The skin of the seat is a mix of diffuse and glossy shaders, with a voronoi texture as a bump map.
In Edit mode, unwrap the tires and use a footprint texture as a bump map. The headlight is a glass shader with IOR set at 1,45 and a texture as a bump map (see this Blender file
for more details).