Closure:
I did very briefly one day play with stuffing a piece of cloth in a couple of the sound holes. Really didn't make a huge difference.
After looking at this thing hanging on the hook next to my Ohana for another month... it finally got back out to the car. (had to get my phone fixed, and knew I'd have to entertain myself without a phone in my hand <gasp!> for an hour or two yesterday)
It works in the car. I was pleased with it in that environment. And that's what I bought it for! A smallish uke to keep in the back seat of my driver's ed car for those times when a student cancels mid-day and I've got time to kill, or when I have lessons that are close together and I have a 45 minute gap between lessons and a 5-minute drive to make.
With the head stock and armrest mods that I've made, it's more playable (for me) than it previously was, and it sounds plenty good enough in the car. I enjoyed jamming on it for a while.