No, I do not believe they should. I was making a structural point-- the regulations on FA firearms decrease supply and make it less likely that a bad guy will have access to them. I was responding to another poster's claim that criminals are already breaking laws, so NFA laws are moot in that community; I don't believe that to be the case, simply because the numbers of crimes committed with FA weapons in this country is infinitesimal, primarily, I think, due to NFA laws. I'm not sure how that point relates to your BMW, but, if I'm to believe the apparent consensus in the thread, I'm an idiot incapable of understanding such things.
NFA laws did not stop the north hollywood shootout. There have been many other documented cases of full autos used. Any dummy with a file can make a full auto.