This link is to a project I completed a few months ago. It has RPC Cars, Trees, People, and Fountains.
http://www.mulkeyinc.com/video/fayettevillestreet-mov.htm
I kept the lighting simple and used a camera map for the shadows for the RPC trees and parked cars. This took between 5-12 minutes per frame, 30 fps for 3 minutes. Probably 40plus hours to render on a 20 computer render farm.
I agree with Eric in how easy it is to underestimate your time on a large render job. I try to do lots of test renders (every 100 frames) before submitting the entire job.
Good Luck on the Job,
-Tim