Abstract: An aerodynamic-gap sealing structure for a tractor-trailer combination includes rigid multipiece articulating shields at rear corners of the tractor and extending rearwardly to engage a side of a front face of the trailer. Similarly, a cab of the tractor is provided with a roof extension pivotally mounted on a top corner of a roof, or roof fairing, of the cab and extends rearwardly and upwardly to a roof of the trailer disposed thereabove. The side shields include a plurality of panels, preferably three, between the cab and the trailer which are pivotally connected to each other by centering springs to allow for varying distances between the cab and the trailer corners as a turn is negotiated while normally maintaining the panels as a straight extension from the cab to the trailer.