The biggest problem with the Maybach is that it is still a MB and looks like an overgrown S Class. The Rolls Royce and the Bentley look sufficiently different from their prospective owners, ie BMW and Volkswagen that there is a perceived difference and a much higher value placed on them.
Sorry, I was at Euromotor's in Bethesda the other day and they had 3 of them sitting on the showfloor. One had been there at least 6 months. Unfortunately there aren't many takers for a $493K when you can get a RR or Bentley for less.
Current: 06 SL500
/ Pewter w/Berry Red Interior/Sprint Booster
06 Porsche Cayenne Titanium
Edition Porsche Red w/2 Tone Camel and Blk Interior