Go further. The manufacture of a Prius uses much more energy than the manfacturing of a similar-sized conventional car. At the end of its life, though, you have so much more that will have to be carefully recycled/disposed of properly. What do you think it takes, energy-wise, to recycle the components of the Prius' battery pack? How about all the on-board electronics? These aren't things you can just heap into the landfill. You can expect at least 25-50% of the manufacturing energy will be needed for every Prius that is safely decommissioned.
It may make people who can not follow the complexity of the issue feel better about themselves, but though the Prius gets great gas mileage it's not a truly "Green" vehicle anywhere but in the halls of Toyota marketing.