Ok, almost. But all the areas that matter.
While I used a needle scaler and multi-tool on the removeable fenders, I didn't want to have another noise complaint, so for the last week I've been going out with an old, cheap wood chisel and using it as a scraper. That did a great job for most parts, but in the area right above the rear wheels (the inner fender) it was on there tough.
So looking on the web for other solutions, I stumbled across someone who recommended an air chisel at its lowest setting. I thought it was worth a try--if it was loud, I'd go back to the hand chisels and just suffer through it.
Fortunately, while loud in the closed garage, it wasn't so loud that it carried much beyond the garage--and it made fairly quick work of the old, brittle undercoating. Oh, and for those who are concerned about my health, I wore a respirator and a face shield while doing this work.
Now back to waiting for an opening at the media blaster.