1. A method of dynamically calibrating a given vehicular camera relative to a reference camera attached to the vehicle, the given camera and the reference camera comprising pixelated imaging arrays, said method comprising: providing a plurality of cameras at the vehicle so that the cameras have respective exterior fields of view, the cameras capturing image data; selecting from the plurality of cameras a reference camera and a given camera, wherein the selected reference camera and the selected given camera have overlapping fields of view; capturing an actual given image frame of image data by the given camera; capturing an actual reference image frame of image data by the reference camera; identifying an overlapping region in the actual given image frame of image data captured by the given camera and the actual reference image frame of image data captured by the reference camera; selecting at least one object or at least a portion of an object present in the overlapping region of the actual reference image frame captured by the reference camera; determining expected pixel positions of the selected object or object portion for a predicted given image frame as would be captured by the given camera based on the location of the selected object or object portion in the actual reference image frame captured by the reference camera; locating, via processing of the actual given image frame captured by the given camera, actual pixel positions of the selected object or object portion as detected in the actual given image frame captured by the given camera; and determining alignment of the given camera based at least in part on a comparison of the actual pixel positions of the selected object or object portion in the actual given image frame captured by the given camera to the expected pixel positions of the selected object or object portion for the predicted given image frame.