My trainer has suggested something that I hadn't considered before. He explained that when he is out mountain biking with his wife, if he gets too far ahead that he will stop by a tree and hold himself up, still clipped in, until she catches up.

His suggestion was that I try something like this with my car - for getting started. Clip in my power foot, brace myself against the car with my hand until I clip in the other foot - and take off with both feet already clipped in. This seems like a reasonable idea - as long as I am careful with the alignment of bike and car. Of course, this wouldn't help at a stop sign/light or a sudden stop in the road, so it can't be the only thing I practice...

I am thinking that my first ride after the parking lot session will be on a paved trail - at least there will be no cars in the equation

NY Biker, thanks for the link!