Never heard of him/her fortunately. google 3D warehouse has a ton of cars, albeit in varying quality and in SketchUp format. Whether it's worth it to get the demo (or the free version and a plugin) to convert them to obj I don't know. Probably OK for background at least. I assume you've seen the ones at http://www.dmi-3d.net/

excellent quality in lightwave format that can be easily converted to .obj with PoseRay if Poser can't import them. https://sites.google.com/site/poseray/ 

Edit: Just came to me you may need commercial use - don't know about either of those sources terms.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken