Car repairs have increased as well. So I'd like a bit more sources regarding your assertions.

> In the 1960's, getting a car to 100,000 miles was an achievement; now, the car is just getting broken in.

The average car reaches 160K miles before end of life: https://en.wikipedia.org/wiki/Car_longevity.

So by 100K miles, 50% of cars have already lived two thirds of their life.