How are there not more negative reviews? I owned this car until it was 8 years old and sold it. Right around the 80-90K mark, the Transmission gave out. I parked it for several months looking into the problem and found dozens of forums out there with hundreds of people reporting the same problems as mine: loss of 2nd gear and overdrive. I talked to many mechanics and they all had seen plenty of these cars come in because of a poor design by Ford, Lincoln, Mercury. These transmissions were used in the LS, Aviator, Mustang, and several others. The design is 2 servo pistons (steel) that go through the Transmission case which is soft Aluminum. Over time the opening gets bigger, losing 2 gears.
Navigation was a great design for those years. Heated and Cooled front seats, automatic windshield wipers, Auto-dimming mirrors, exit assist (seat moves all the way back when car is turned off), great rear speakers provide low bass in the Navigation package.
Transmission costs 75% of owners around $3000-$4000 to repair. Replacement will not solve the problem because the new transmission, if no brass bushing is installed around the Servo bores, the same problem will happen anywhere from 40-110K miles and the transmission will lose pressure for those two servos. There are plenty of forums out there. Google 5R55 Transmission Servo problems and you'll come across plenty.
Save yourself $1000s of dollars of repair work and trouble. Or look for one that has already had this repair work done properly (Brass bushing installed) and then you're good to go and have an amazing car.