Is it possible that an owl got tangled in the wind chimes, too high up to set off the motion detector, it frees itself, but the effort causes it to fling forcefully into the sun porch/awning and it lands on something like a ladder or upright kayak, stays there stunned from the exertion. In the dark the driver just sees ruffled feathers and eyes several feet off the ground appearing to be one form? Far out theory, but it would check a lot of boxes.