I purchased my 2007 Lincoln Town Car Designer here in January 2007. That was a great experience.
In 2008, the fuel sender needed replacement. They installed it wrong as the Full needle was 180 degrees off. I found this out right after the car was serviced while at a local gas station--the needle indicated EMPTY after I added 15 gallons of fuel. As I drove the needle slowly moved towards full depending upon how far I drove. I had to bring it back for them to correct this once the actual fuel level was guessed to be 5 gallons remaining.
In October 2013, The Driver's Door Module failed and a dealer had to repair it as it needed a factory computer download for my vehicle. I knew what it was and made a call for service. The service writer---correct term--told me my car didn't have a DDM. He went on to explain how a Lincoln operated. However, he end up describing how a 44 year old Lincoln worked in great detail! I was impressed that he was living and working 44 years in the past! OMG they will not be working on my car since this was their second strike out. FYI--my car has approximately 10 modules that control other functions.
In December 2013, I sold my 2007 TC and wanted to purchase a new 2014 Navigator. I told them exactly what I wanted--two rows of bucket seat with consoles. They emailed information on vehicles with second row bench seats. Over one week latter they called me to see if I liked the vehicles they emailed me. The funny thing was, minutes before their call I purchased what I wanted at a different dealer.
My opinion: Sanderson might be a great place to purchase a new vehicle IF they have what you need.
As for service, NO WAY as the service writers, I was exposed to, do not understand the operation of the vehicles that the dealership sells.