Which cars hold their value in Ireland?

Take one model year — a three-year-old car, say — and find the median DoneDeal asking price for it in the earliest year we have enough listings, and again now. The difference is what that year of cars actually lost while it aged, and it is what the table ranks on. Both ends need ten or more listings, or the model gets no place in the ranking rather than a figure resting on three ads.

These are asking prices, not sale prices. They describe what sellers want for a car today against what sellers wanted for the same year of car back then, which is not the new list price it was first sold at and not what any one car fetched at the gate. A model with several listings of the same ad number is counted once, and sterling listings from the North are left out because a price without VRT in it is not comparable.

The “fitted rate” column is a different statistic and is shown only beside the model years it was fitted over: a least-squares fit of the median against age, which measures the span of years it had to work with as much as it measures the car. That is exactly why it is not the ranking — a model whose oldest listings are ten years old and one whose oldest are three would be sorted by their samples.

One honest caveat about the bottom of the table: a model that changed generation in the window, or an electric car whose whole market repriced, is yesterday's shape against a new one rather than simply an unloved model. A new generation is part of what depreciation is, but it is not the same thing as a car nobody wants.

Ages with fewer than 10 listings are left out, because a handful of dealer ads on a nearly-new model flatters year one.