I get sick on long car journeys, but can survive plane and train journeys.
car breaks down
Check out the Obusforme Backrest Support series. I have used it with great results as the bucket seats are the not the most comfortable on long drives.
Of the 3 in the categories you chose the lincoln will be the most comfortable.
Bently
Any large 4 door sedan will be the most comfortable but not the most fuel efficient.
That is subjective. What is comfortable to you or me may not be comfortable to others. In most case the more expensive the vehicle the more comfortable the seats.
2010 M6
i believe the most comfortable car seats in the world are the seats from the Volvo S80 from '99 to '07.the new generation lost something.
Mercedes s class
Mercedes S Class
Brett's tank seats.