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If you upgrade to the Game Dev edition you can then optimize the car for Unity.  In essence, you are buying the rights to use the mesh in your game.

Standard license is limited to 2D renders and 2d animations.  Those where neither the texture or the mesh can be extracted. 

I think this is misleading. Using Poser Game Dev version does not license just any content to be used in Unity. That could onlyapply to the content that comes with game dev. So if this car model is part of Poser's included stock content, in the game dev version, then ok. Anything else, you would have to ask the legal owner of the content you're using what the license restrictions are. Chances are pretty good that that license fee will be higher, but every content artist has their own rules and restrictions on whether their poser content is allowed to be used in game engines. Just because you are using the game dev version of Poser does not change that.