At first glance, a new set of spy photos shows what appears to be a Hyundai Genesis sedan that has been stretched. But according to Automobile Magazine, what we are looking at is the next-generation Equus flagship.
The mule appears to be riding on a longer wheelbase. This is hinted by a large piece of sheetmetal riveted behind the rear doors. Also giving some credence that we're looking at the next Equus. Driving along with the mule was a BMW 7-Series.
Not much is known about the next-generation Equus, but Automobile Magazine speculates that the model will share the Genesis' platform and come with the option of all-wheel drive. As for when we'll see the model, 2016 or 2017 seems very likely.
Source: Automobile Magazine