Any change you're getting exhaust condensation onto the camera?I can't imagine an autofocus feature being part of the camera since it's always pointed at the same angle and fixed point. I'm wondering if the backup lights may be "blinding" to camera, especially if your driveway/garage floor are coated with a light color and/or reflective surface. I know that may be reaching. My driveway is surfaced in very light blue. I will attempt to replicate your problem tonight. BTW, this only happens in your driveway/garage?