At last I've finished this futuristic motorcycle based on a Lambreta design. I've used Cycles for the final render.
In the normal scene file there are three different scenes. One the scene itself, another to render only the lights and one for the composition.
The montage file also have three scenes. One to render only the motorcycle, another for the shadows and another one for the lights, the composition is made in the scene named "mota".
The background image is from travfotos and you can download it at http://www.fotopedia.com/items/flickr-3920728321 (not included in the .blend file)
The textures are from PlainTextures (http://www.plaintextures.com/)
The HDRI environment map is from OpenFootage (http://www.openfootage.net/)
you can see more renders at http://blender.ruijst.com/2012/01/15/lambreta-xp70-rendered-with-cycles/