Motto in software projects: always start small, add features later.
Rules in software projects:
1. once the speccs are done, and contract signed, NOTHING gets added
2. nothing goes live before all boxes are ticked.
3. changes are to implemented with agile-like methodology.
3.1 AGAIN, nothing goes live before all boxes are ticked, including any new features recently added.
3.2 goto 3.
Why Hertz decided going live with a website from hell is anyone's guess and they hired Accenture, which is enough evidence for me. Accenture is #SureToFail - it's the Craptita for the rest of us.