Another blogger had to get rid of a vehicle recently.
In his case, he had a Jeep which developed engine trouble...of the kind that rapidly turned into too-expensive-to-be-worth-fixing.
He ran into one of the long-term-ownership problems in the automotive world. Almost all vehicles are now made to have near-zero maintenance trouble. For something like 8 to 10 years.
But most vehicles have design problems that will begin making ownership expensive. Sometimes these problems are foreseeable, sometimes not. Sometimes they arrive shortly after year number 8. Sometimes they wait until 12+ years.
Sometimes they are avoidable. My current vehicle, a Subaru, suffers from potentially-catastrophic failures to the timing belt. These tend to come somewhere between 100000-miles and 110000-miles. However, the belt can be replaced before this becomes a problem.
Other times, these problems are not avoidable. An earlier car I owned (early-90s Taurus) had transmission trouble. This model of car, though extremely popular, regularly suffered transmission failure at ~80000 miles.
Robb's Jeep had a different category of problem, but one with similar results. The engine failed, and in a way similar to most other Jeeps of that model-and-age combination. Thus, most junk yards have such vehicles, but few have replacement engines handy. (Robb noticed that the salvage yard had 10 such Jeeps, 8 of them with the same engine failure. And two engines that did not have such a failure, but required expensive rebuilds anyway.)
And in his case (as with my old Taurus), the cost of repair is more than the resale value of a good, working vehicle of that type.
One of the frustrations of buying used cars is that such things can creep up on the unwary buyer. Yet one of the frustrations of buying a car new is that after you keep it for a decade, you want it for another five years...and problems like this can also sneak up on you.
Like Robb said, it's a First World problem.