Someone asked me last week, over email, a question that sounds simple: "what's the most common used car brand in the world, according to your data?" I said I'd get back to them in an hour. It took five days, on and off, because the answer kept generating better questions than it answered.
Here's the log, roughly as it happened.
Monday: the easy part
I pulled the global top-15 makes across our 1,108,535 live listings. Toyota leads at 91,730. Volkswagen is right behind at 84,580 — an 8% gap, which is closer than I expected given how much of the used-car conversation online treats Toyota's dominance as a settled fact. Then Mercedes-Benz (61,336), Hyundai (60,937), BMW (56,740), Ford (52,982), KIA (52,928), Audi (48,471), Nissan (42,342), Renault (41,587), Peugeot (38,805), Honda (35,029), Skoda (30,022), Chevrolet (26,057), Volvo (23,597).
I sent the client the number and the list. Should've been done there. Wasn't.
| Rank | Make | Listings |
|---|---|---|
| 1 | Toyota | 91,730 |
| 2 | Volkswagen | 84,580 |
| 3 | Mercedes-Benz | 61,336 |
| 4 | Hyundai | 60,937 |
| 5 | BMW | 56,740 |
| 6 | Ford | 52,982 |
| 7 | KIA | 52,928 |
| 8 | Audi | 48,471 |
| 9 | Nissan | 42,342 |
| 10 | Renault | 41,587 |
| 11 | Peugeot | 38,805 |
| 12 | Honda | 35,029 |
| 13 | Skoda | 30,022 |
| 14 | Chevrolet | 26,057 |
| 15 | Volvo | 23,597 |
What kept nagging at me was the shape of the "German bloc." Mercedes plus BMW plus Audi comes to 166,547 — nearly double Toyota alone, and Toyota is the single biggest name on the list. Stack Hyundai and KIA together and you get 113,865, which quietly outguns any individual non-Toyota badge except Volkswagen. Grouped by country of origin instead of by badge, the leaderboard rearranges itself completely. That's not a new insight to anyone who's spent time in this data, but seeing the arithmetic land in front of me at 11pm on a Monday still felt like something.
Tuesday: the wall
I wanted to go further — which region is driving Toyota's number, is it breadth across markets or a pile-up in one or two — and hit a wall I should have seen coming. What I have is two separate aggregates: top makes globally, and top regions globally. I don't have the cross-tab, the actual make-by-region matrix, sitting in front of me. Building that properly (not eyeballing it) is its own job, and it's now on the list of things to ship rather than something I can fake my way through with the numbers on hand.
So Tuesday was mostly a diary of failure. I wrote "need make×region breakdown" on a sticky note and moved on to what I could actually check.
Wednesday: the one that held up
Here's the check that survived scrutiny. France is our single biggest region at 67,569 listings. Renault and Peugeot combined come to 80,392 globally — more than the entire French regional total, by a comfortable margin. Even if every single French listing were a Renault or a Peugeot (it obviously isn't — French roads are full of German and Japanese cars too), the math still requires those two brands to have a large, real presence outside France. Belgium (35,670), Portugal (31,909), Poland (32,821) — any combination of the mid-sized European regions closes that gap easily.
It's a small thing, checking whether a brand's global total can even fit inside its "home" region's total. But it's the kind of sanity check that's easy to skip and occasionally catches something. In this case it confirmed what I'd assumed rather than upending it — Renault and Peugeot are genuinely pan-European, not a French-only story with a big flag planted on it. Still, I like having done the arithmetic instead of just asserting it.
Thursday: the number that's low for the wrong reason
Chevrolet at 26,057 looked light to me, given GM's global manufacturing footprint. Then I looked at our USA regional total: 48,127. That's smaller than France, Japan, UAE, South Korea — smaller than Brazil, even. It's not that Chevrolet is a niche brand in the real world; it's that our US source coverage is still thinner than our European coverage relative to how big that market actually is. We're at 1,375 sources across 73 regions now, and growth hasn't landed evenly — Europe got dense faster than North America did. Chevrolet's number here is a coverage artifact more than a market-share signal, and I'd have gotten the wrong read on the brand if I hadn't checked the region size first.
Friday: closing the notebook
Last thing I checked, mostly out of curiosity: Volvo sits at 23,597 listings, and Sweden — its home region — totals 28,017. Those two numbers are close enough that Volvo's global count could very nearly fit entirely inside Sweden's regional total, which is a different pattern than Renault/Peugeot's. Whether that means Volvo's international used-car presence in our data is thinner than its domestic one, I can't say for certain without the cross-tab I don't have yet. I'm noting it rather than concluding it.
Somewhere in the middle of all this the deal monitor kept doing its job in the background, flagging 12,823 under-priced listings across the same week without needing me to check its arithmetic at all. There's something almost restful about that, next to five days of me redoing multiplication by hand because I didn't trust the first pass.
The actual answer to the original email — "what's the most common used car brand in your data" — is Toyota, by about eight thousand listings over Volkswagen, out of 91,730 total. That's the whole answer, technically. It just took me most of a week to earn the right to say it that plainly.
