Generation is a hard boundary
991.2, 992.1 and 992.2 remain separate primary markets. Transmission stays visible within each generation. The site never calculates a single blended Touring valuation.
Comparable cohorts narrow in order
Generation, transmission, mileage, paint program, seat type, brakes, front lift, meaningful factory specification, originality and history.
Package components remain separate facts in the source record, but correlated components are not stacked into fictional additive premiums.
Vehicle and market event are separate
The same physical car keeps one Vehicle ID. Each return to market creates a new Market Event. A continuous listing keeps the same event and adds price observations.
DME reports, mileage, service, paint and track-use evidence are dated observations. New evidence never overwrites the earlier record.
Charts earn their space
Scatter plots require at least five valid observations. Trends require at least eight observations and enough mileage dispersion. Time series require at least three distinct periods.
Malformed or suspicious prices are withheld from charts and medians until validated. When the sample is thin, the underlying records replace the chart.
Asks and bids stay separate
Dealer and private-party points are asking prices. Auction points are current bids and use a distinct marker; they never enter an asking-price median.
Ask trends and ask-versus-sold comparisons require consistent generation, transmission and specification cohorts with adequate observations on both sides.
Private source, public evidence
The public site receives a validated market snapshot only. Source credentials and the private data connection never ship to the browser.
Unknown remains unknown. It is never converted to no.