Sonix points out on Elysiun that Honda has posted heaps of freely available DXF models of 20 products (cars, racing bikes and even a robot) on their website.
I'm not sure about the license (maybe a Japanese reader can help out), but I'm sure you can have lots of fun with these. The only downsite: you have to download each model part by part and put them together yourself. Hmmm... this brings back memories of childhood when I used to build airplane models :)
You can get the models here, and Blender will load them with the regular 'Open..' function (no need to use import..).