Draco pistol bullpup kit.

Somehow, for some reason, this doesn't seem to qualify as a SBR.

http://www.cbrps.com/Products.html

In essence, it appears that this is an ATF classified pistol which can be fired from the shoulder, and stays totally legal as a pistol so long as you don't put a forward grip on it.

So long as I'm not missing something, might this be a good bet for long gun performance carried concealed/loaded in vehicles under a CPL?

The quote says the new design is not an AOW ("and thus would not be regulated under the provisions of the NFA in any way"), but I would love to hear someone at FTB explain why a Glock with a stock is an SBR and this isn't.

While trying to make sense of these things is generally a bad idea since the laws tend not to be logical, I will venture to guess that the stock add on with a glock is there to be a stock, whereas in this case, the grip was moved forward but the back of the gun stays the same pretty much. Further, when you look at the sights they are set in such a way that you can't really reference them from a shouldered position, granted though that a good laser or a red dot sight would take care of that in short order.