Auto-calibration of stereo cameras installable behind the windshield of a host vehicle and oriented to view the environment through the windshield. Multiple first image points are located of one of the first images captured from the first camera at a first time and matched with first image points of at least one other of the first images captured from the first camera at a second time to produce pairs of corresponding first image points respectively in the first images captured at the different times. World coordinates are computed from the corresponding first image points. Second image points in the second images captured from the second camera are matched to at least a portion of the first image points. The world coordinates as determined from the first camera are used, to solve for camera parameters of the second camera from the matching second image points of the second camera.