To use this 4WD Car with Raspberry Pi, does it nee a motor shield?
It will need something in order to drive 4 motors. You options are to use an arduino with a shield that can drive 4 motors. Or you can try and build an expansion for the PI that can drive 4 motors. The Raspirobot board by Simon Monk will drive 2, but you could easily use an arudino with a shield and just communicate with it via serial from the PI.
Hope this helps.