I actually did it! And the recorded lessons are... not bad!
Driving to work this morning, I listened and practiced the letters, the words, the lips, the M... I got through about 6 of the 11 lessons in all. And the exercises are reasonable for drive time. Not too involved, Not too distracting, but do-able. All and all, I had the right idea.
I can already tell I will want to re-record all of the lessons. Leaving enough time to repeat in a "listen and repeat" exercise is really important; There's a whole bunch of stuff to fix that way.
And as the speeders zipped by me, I didn't get any looks that said, "Hey, that guy's talking to himself."
That is, though small, the most important victory, isn't it?