Just before I found MMM, we sold a 1998 Volvo S70 with about 120,000 miles on it. It was 14 years old at that point, had started needing more maintenance more often, and the backseat room wasn't great for our growing girl.
We replaced it with a new Honda Crosstour - acres of backseat room and comfortable for my husband, who has lower-back issues. But it's not as comfortable as the Volvo on long trips, and it doesn't have that "safe as houses, solid as a rock" feel that the Volvo does.
I'm already looking a decade out, thinking about going back to Volvo when the time comes. Will we buy new? We might. We drive cars a long time, and I like knowing the whole history of the car - who drove it, in what conditions, and how it's been cared for. A luxury? You bet. But a worthwhile one, in my opinion.