Would you be up for taking it apart and remaking it using the car print alternating with the blue as a solid block without the red, yellow, blue and green squares? Maybe you could applique the larger car prints on some of the blue squares. Or do a disappearing nine-patch with the car print in the corners, the red in the center and the blue squares in the "north, south, east and west" positions. This will be a darling quilt for your son.