The correct GPU driver depends on your OS X version. There is pretty much a different GPU driver for every OS X version. If you are using Mountain Lion, the native driver is correct. If you are using something else, you can find the correct GPU driver for the Quadro 4000 on the NVIDIA driver download site, by giving it your OS X version. Link below:
http://www.nvidia.com/Download/index.aspx?lang=en-us