Tethered to a crane? Their confidence in the craft seems a little lacking.

Garbage. This stuff will not be practical and affordable until it's fully electric and autonomous. The space requirements for flying vehicles (even VTOL) is too big for it to really go mainstream. Imagine 3 million people a day commuting in and out of NYC by air. Or going to the mall. Just not practical. It will be just fine for weekend cruises or shortish (2 to 3 hours) trips. There it hands down beats cars and the landing/take-off issue would be less of an issue for a lot of trips. Unless EVERYONE uses it. But then again, very few people (as a percentage of the total) do trips on the weekend.

"...the original four-seater M400 prototype unit – which actually flies..."
Ah, no it doesn't. Granted it did lift off the ground (or at least appeared too) under its own power but, if you notice, it was unmanned. There's a reason for that.
And, as Nik mentioned, it was tethered. It has never "flown" untethered. Again, there's a reason for that. There is also a reason why the Moller Skycar has been in "development" for over 50 years.
And let's not forget that Paul Moller was sued by the SEC for civil fraud.

"If the buyer wishes, however, they can work with Moller to have numerous upgrades made, so that it gets FAA approval."
Please stop peddling this BS.
If Moller couldn't do it with 150Million Bucks, they ain't doing it for you.

I have been wondering about the Moller Skycar- is has graced the pages of the Popular magazines for many years. It was always intended to be autonomous, and the thrust vectoring and multiple engines were brilliantly conceived. Why no further development? Shortage of funds is my best guess.

Of more interest (to me, at least) is the Cartercopter. It is at a much more advanced state of development, and Carter has announced an agreement with Mooney Aircraft this year.
Carter claims that their "Slowed-Rotor Concept" can be scaled-up to the size and load-carrying capacity of the C-130 Hercules. Fascinating.

I lived near the Moller showroom 40 years ago. After making an appointment, I went to verify and possibly invest, if they could convince me they were viable. I saw their prototype with ropes around it. No touching. My mechanic was not allowed to verify. I was told I could see a demo "after" I invested (a lot).
Twenty-five years later a friend at work, Mel, told me he invested his life savings about the time I was there. He had not seen a dime, nor could he sell his "share". His lawyer told him he was scammed. Five years later Mel died, and his widow told me that "investment" was the biggest financial mistake they ever made.

Kpar: Yeah,I think the Cartercopter concept is cool too. Always liked gyrocopters.

This thing and the money sink has been around for 30 years or more. The concept and engineering is fantastic and inspiring. However, the real deal never appeared and after a couple of years I concluded it was a scam and probably still is. Wanna buy the Brooklyn Bridge?

Back in 1981 as a young pilot and all around aviation enthusiast, I was introduced to Mr. Moller by my then girlfriend's stepdad who had invested in the Skycar project. He was certainly engaging in a Burt Rutan meets P.T. Barnum sort of way. I followed his progress, or lack thereof over the years and although he could barely raise the machine off of the ground he was quite adept at raising lots and lots of cash! I would call his ambitions pie in the sky, except pie is much more aerodynamically sound than the Skycar. This story seems to be like the Phoenix in that it is resurrected every couple years by some lazy journalist who believes there is something newsworthy about this endeavor, very inappropriate, especially now as there are so many legitimate projects on the horizon.