Methodology
How BimmerWorth is designed to value a BMW
This page describes the intended methodology of a platform that is still being built. It is a statement of design, not a description of a system that is currently running.
Inputs the valuation is being built around
Each of these is intended to appear as a named, visible factor in the breakdown, with a direction and a reason attached.
- 01
Base market range
The starting point is the range a given generation and trim transacts within — established per chassis rather than per badge, so an E92 and an F30 are never treated as the same car.
- 02
Vehicle specification
Factory options and packages, transmission, drivetrain, seats, wheels and paint. Specification is intended to be an explicit, visible adjustment rather than an assumption folded into the base range.
- 03
Mileage
Assessed relative to what is typical for the generation and age, not as a single linear penalty. On older chassis mileage is designed to carry progressively less weight than condition.
- 04
Condition
Paint, panels, interior wear, wheels, tyres and mechanical state, described in defined grades so that the same words mean the same thing between two valuations.
- 05
Maintenance history
Weighted by whether the documentation addresses the service items that are actually discussed for that engine family, rather than by the thickness of the folder.
- 06
Accident and title history
Disclosed, documented repairs are intended to be treated differently to structural damage or a branded title. The distinction should be visible in the breakdown.
- 07
Modifications
Assessed on reversibility and whether original parts are included, rather than on what the modifications cost.
- 08
Regional demand
The pool of buyers for a specific configuration is not evenly distributed. Location is intended to adjust the range, not to be ignored.
- 09
Comparable listings and transactions
Comparisons against similar cars, weighted by how closely the specification actually matches. This requires a data pipeline that does not exist yet.
- 10
Confidence scoring
A stated measure of how much corroborating input a valuation had. A car described in detail with full documentation should score higher than one described in three fields — and the interface is designed to say so plainly.
Why explainability comes first
A single number with no reasoning behind it cannot be checked, argued with, or corrected.
A valuation is only useful if you can see how it was reached. If a figure seems wrong, you should be able to look at the factor list, find the input that caused it, and either correct the input or disagree with the weighting on an informed basis.
That is why the interface is built around a factor breakdown and a confidence score rather than a headline number. It is also why the confidence score is designed to fall when information is missing, instead of quietly filling the gaps with assumptions.
Limitations
BimmerWorth valuations will be estimates, not guaranteed offers, certified appraisals, or substitutes for a physical inspection.
- No dealer, buyer or insurer is obliged to honour any figure produced here.
- A valuation reflects the information you supply. Inaccurate or incomplete input produces an inaccurate estimate.
- Mechanical condition cannot be assessed remotely. A pre-purchase inspection by a qualified technician remains necessary.
- Markets move. Any estimate reflects a point in time and has no guaranteed shelf life.