Ross put his comments very well, perhaps the rest of us were less articulate. I think that what we were all trying to say is that in the durability of any vehicle, the abilities and attitudes of the driver are an inseperable part of the durability equation, as is the locations where the car is driven.
If the driver has an attitude not "wasting money" on maintenance on the car, and drives hard, the car won't last. If the driver has poor skills or judgement, even if he/she maintains the car perfectly, the durability of the car will be diminished by accidents, especially if it is totalled. If the drivers normally excellent skills and maintenance programs are impaired by illness, chemicals, emotions, memory problems, whatever, the durability will be affected because maintenance was overlooked or improperly performed, or the car was pushed too hard for the circumstances. If a car is driven hard year round in So Cal, it will probably still last longer than one that is driven hard in a climate with lots of fine grit blowing through the air in the summer, and salty snowy roads in the winter. If 2 cars are driven hard in SoCal, and one is pushed by someone who has track skills in smooth driving, while the other by someone who is abrupt in their gear changes, cornering, and braking, my money goes to the smooth "hard" driver.
I repeat, it is not about age, it is about driver attitude, skills, and abilities. My 80+ year old parents MB required several thousand dollars of work because they forgot to do normal maintenance due to impaired memory. One of my neighbors, going through a divorce, needed a new engine in their turbodiesel because neither he nor his spouse would do the maintenance because they didn't know who would wind up with the car, and each of them believed that they were hurting the other by neglecting the car - their emotions got in the way of their knowledge.
This is a pretty caring board, and nobody was trying to offend you or put you down because of age. We were just trying to explain that unless the car is being run only on a Dyno Bed in a Clean Room, and controlled only by a computer, that a lot of different and seemingly unrelated factors can influence durability.
Enjoy your ride, and if you and Ashman would still like to get coffee sometime next month, I'd love to see your car.
2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)
Click to see 87 300E