About to start a second class project, Jay Gatsby's car & the face of his Mansion. Any Tips?

Some people know that I’m working on a game for a class project already, but this is for a different project. This project is for my Humanities class and it’ll be based on the critically acclaimed book, “The Great Gatsby”. The main focus of the scene is going to be the car Jay Gatsby presumably drives, the Rolls-Royce Silver Ghost, and a portion of the front of the mansion.
I’ve already got some reference pictures for making the 3D models, but I’m not sure how to handle choosing good textures, using/ getting UV maps, and just making an overall good render. I will not be modeling the whole mansion only a portion of the face of it (if you won’t see it, don’t make it mentality). This is my first still/ detailed scene, any tips on going about this? (I also only have roughly seven hours to do this). Thanks ya’ll. :slightly_smiling_face:
DUE TO HARDWARE CONSTRAINTS I HAVE TO USE BLENDER 2.75b!