I read through the discussion (which is from 2007). Seems like the issue is more around BMW of Manhattan and the sub-par customer service that particular dealership reflects.

The search results image posted above was from about a month ago... Here's another search I just did from this afternoon. Several M6 and M5 cars are listed on there. Best thing to do is call the specific dealership that has each of these cars listed from the BMWUSA.com website, (attached).