My parents are considering the Model S, but neither has a smartphone. How will this degrade the user experience of owning a Model S? Can they do things like preheating the car and checking status from a web browser?
What area of the country do they live (does it get very hot or cold)? Ask them if they would find it useful in the winter to walk out to a heated car after going out to dinner or someplace else for example. If they wouldn't find that useful and don't travel much that takes away two of the main features of rne app (preheating/cooling and monitoring your charge on the road).
To me being able to cool or heat the car from anywhere I have an Internet connection is one of the best features but they might not find it that useful.