\section{Conclusion}\label{sec:conclusion}

Using a daily panel of every listing published by 131 dealer websites, two full-inventory portals and five dealer groups in Quebec over eleven weeks of 2026, we have described how the price of a used car is discovered on the dealer's lot. Asking prices depreciate nonlinearly in age and mileage; one listing in five is cut, by 2.8~percent at the median, with a markdown hazard that doubles over the first three weeks; overpriced vehicles are cut sooner and more deeply; and listings disappear after nine days at the median, faster for cheap, high-mileage and older vehicles. Repricing co-moves across neighbouring dealers on the same day and at weekly harmonics but not with a lag, which we interpret as common shocks and shared routines rather than strategic reaction. Quality-adjusted asking prices differ across the province's regions by at most a few percent, and not detectably once trim is held fixed. A transparent five-component liquidity index summarises more than half of the common variation in regional turnover, and its non-exit components anticipate next week's exits under the preregistered standardisation, less clearly under alternatives; the data also tell us that deep markdowns are a sign of slow, not liquid, markets.

The limits are as important as the findings. Asking prices are not transaction prices; exits overstate retail sales by at least a tenth, as our relisting analysis shows; the competitor event study is descriptive; the regional null applies to one quarter; the thirty-day predictability of repricing is mostly dealer practice and does not transfer to unseen dealers; and the liquidity index has no external validation yet. A longer panel, matched to registration transfers, would allow the markdown and exit hazards to be modelled as competing risks with a verified sale outcome, the regional null to be tested across seasons, and the index to be tested as a leading indicator. The pipeline that produced this paper, with its immutable snapshot, exclusion log, preregistered plan and claims ledger, is designed to make that extension a matter of rerunning it.