you could run a car with out an intake no problem, yes you will be losing a little bit of torque but nothing noticable if its your daily. its just not recommended because 1. the positioning of the intake, all your gonna be sucking in i hot hair blown back from the engine and radiator, and 2. you are going to be sucking in dirt and debris from the road under the engine as well as dust and dirt from the engine bay which can potentially not be healthy for the engine.
if your running no intake just to get around say to the auto store and back, then yeah go right ahead, no problem BUT i wouldnt do it for a prolonged distance/time