To be honest, I really have no clue about YourRide in specific...
However, from driving around property and resorts all day long, and seeing typical traffic... My guess is that they use fairly new Lincoln Towncars, and for limos, a stretched version of the Towncar. Those are mostly what I see around property. Most are black, some are white.
As far as I know, Disney itself is the only one around here that doesn't use Lincolns, but rather Cadillacs.
Once again though... that's just my best guess.