Surprised that GM didn't drop Cadillac. From my experience I find that Lincoln Town Car is greatly preferred to full size Cadillacs. The general consensus is that Cadillac is junk, inferior even to Chevrolet.
A limo service told me that they haven't used Cadillac in years. Because they break down a lot and always in the shop. Towncar owners are repeat owners many on their 3rd or 4th Towncar. Towncars are built on same chassis and engine as the Ford Crown Victoria, a very reliable long lasting popular police car and taxi cab.
GM was a fool to keep Cadillac and get rid of Saturn. Cadillac should of been shut down 10 years ago. Most used Cadillacs are driven by uneducated, poor, ghetto dwellers or white trash.
PS: If you looking for a used car never buy a Cadillac or Audi. both overrated and very unreliable.