How the numbers work
Worth the Drive exists to answer one question with evidence: what does the money actually buy? Here is exactly where our numbers come from and what they can — and can’t — tell you.
Where the data comes from
Every price on this site is a real hammer price from a public UK auction result — currently sourced from PistonHeads Sold Auctions and Collecting Cars. We record the sale date, price, model year, mileage and specification text exactly as listed. Nothing is scraped from classified asking prices, which routinely overstate what cars actually change hands for.
How a sale is matched to a car
Each car family (say, Porsche 911) claims auction results by make and by generation keywords, so a lot titled "997.2 C4S" counts as a 911 even though the listing never says "911". Within a family, trim keywords narrow the pool further — "GT3" lots feed the GT3's numbers, "111R" lots feed the Elise 111R's. Matching rules are data, not code: we tune them as listing conventions evolve.
The retained-value figure
A trim's "retains X%" figure is the median sale price of its matched auction pool, divided by its original UK list price. We use the median rather than the mean so one concours-condition outlier or one crash-damaged bargain doesn't distort the picture. The pool sizes are shown honestly: when a trim has only a couple of matched sales, treat the figure as directional.
When you see "estimate"
If no auction results match a specific trim yet, we fall back to sales of the wider model family from that trim's own generation onward — and we say so, right under the gauge. If even that pool is empty, we show "insufficient auction data" rather than inventing a number. As new auction results are imported, these labels disappear on their own.
Value for money, not just depreciation
Depreciation alone doesn't tell you what to buy. We compute pound-per-horsepower at today's auction prices, power-to-weight, and the direction prices are moving (comparing older sales against newer ones, only when there's enough data to mean anything). A car that fell hard early and has now levelled can be the smartest money in the comparison — the site is built to notice that.
The written verdicts
Comparison write-ups are drafted by AI (Claude), grounded strictly in the data above — specs, matched auction figures, and a synthesis of professional reviews. Where a figure is an estimate, the AI is instructed to flag it, not assert it. Auto-generated verdicts are labelled as such on the page and queue for human review; edited and approved ones carry no label.