How we compute · Last reviewed 2026-09-14

TrothStone vs heycar

The difference in one line

heycar is a curated used-car marketplace: it lists dealer stock that meets its quality bar and handles the purchase online. TrothStone curates nothing and sells nothing — it scores the whole market against a published model, then links out to the seller. heycar is the right tool when you want a pre-vetted stock list. TrothStone is the right tool when you want to know what any car should cost and what it will cost to own.

heycar is a curated dealer-stock marketplace. TrothStone is a scoring layer over the whole market, curated or not.

At a glance

	TrothStone	heycar
What it is	An uncurated research surface: everything scored, nothing sold.	A curated marketplace for dealer-owned used stock.
How it makes money	Nothing today. No dealer pays for placement or position.	Fees from dealers on listings and completed sales.
Selection model	Comprehensive: the corpus is scored wholesale — grades A–E flag the good and the bad rather than hiding them.	Curated: heycar decides which stock and dealers make the list.
Price view	Asking vs modelled fair price, deal grade, and per-listing true cost of ownership across the entire corpus.	Dealer asking prices within the curated stock.
Ownership cost	Depreciation + interest + fees modelled per payment method, plus a published 36-month resale forecast per car.	Finance quotes at checkout.
Accuracy you can check	Published and reproducible: RMSLE 0.161, MAE ~£1,770, backtest on 770 cohorts.	No published pricing-model error.

heycar's bet is curation: dealer stock that passes a quality bar, purchasable online. TrothStone's bet is comprehensiveness with scores: nothing curated out, everything graded, nothing sold. This page sets out where that difference matters — and where heycar is simply the better tool for the job.

Curated stock and scored stock are not opposites. heycar's quality bar genuinely excludes some of the worst dealer adverts — write-offs mislabelled, mileage discrepancies, dealers with consistently poor reviews. That is useful. TrothStone does the same kind of filtering by another route: the deal grade. Anything below 0.70 of the modelled fair price is quarantined (grade X) and never appears in search results; grade E flags the rest. The difference is that curation hides the bad cars, while scoring shows them with a label.

For a buyer, the practical difference is: a curated marketplace pre-filters for you, so your shortlist starts smaller and cleaner; a scored marketplace hands you the whole market with grades attached, so the shortlist starts larger but you see the trade-offs. Both are valid buying strategies; one is not inherently better than the other. The point of this page is to set the two out plainly so a buyer can pick the strategy that matches their appetite.

The marketplace model has implications for how prices are set. heycar's curated dealers pay to be there and the platform takes a fee on completed sales; that aligns incentives between the marketplace and the dealer in ways that can be either helpful (cleaner stock, consistent presentation) or unhelpful (margin built into the price the buyer sees). TrothStone has no fee, no inventory, no position on whether the buyer chooses a particular seller. The outbound link on every score goes to the source advert, so the buyer takes the analysis to whichever seller they prefer. A fair-price model with published error bars is only credible from a seller with nothing to sell.

What this page is NOT

Not advice. Figures are model estimates for information only — not financial advice. Representative rates, not offers.
Not a comparison of every dimension. This page describes the structural difference between the two products, in plain English, with links to both sides.
Not UK-general. TrothStone scores the UK market only; heycar may cover more.
Not a sales pitch. TrothStone has no checkout, no lead forms, no paid placement. heycar's own site is the right place to evaluate their product.

Questions people ask

Is TrothStone a competitor to heycar?

Not in the transactional sense — TrothStone sells nothing and never takes a listing fee. It competes only for research attention: before you buy from heycar (or anyone), TrothStone can tell you whether that specific car is priced above or below the market and what it will cost per month to own.

Why score uncurated listings at all?

Because the market includes cars you would never buy, and the score is how you spot them. Quarantine (grade X) and E-grades exist precisely so overpriced or suspect stock is visible rather than filtered out — you see the whole market, 417,146 listings, with the grades doing the curation.

Which should I use to find a car?

Both, in order. Shortlist on a marketplace — heycar's curation is genuinely useful. Then run the shortlist through TrothStone for fair-price, deal grade and true-cost-per-month before you commit. The outbound links preserve attribution: every score links to the original advert.

See the difference on live data

Every claim above reduces to one habit: before you buy any car, check what the market says it is worth and what it costs per month to own. Browse 417,146 scored listings, or read how the numbers are computed.