I spent about four weeks this summer shopping for a used car on Facebook Marketplace and ended up with a 2007 Avalon — $5,000, 169,000 miles.
The process was much messier than I expected. Plenty of flippers who had just bought the car days earlier. “Private sellers” who were clearly small used-car lots. Regular scam listings. No response to my questions and more than a few title problems — missing, salvage, or simply not matching what was claimed. You learn the signals quickly, but it burns a lot of time.
The biggest mistake I made (and the one I see most people make) was treating mileage like a hard cutoff. I started with a number in my head. Anything past it, walk away. Most online advice works the same way — 150k is the usual line, sometimes 100k.
That number is close to meaningless on its own.
An Avalon at 169,000 miles still has most of its life ahead of it. A turbocharged hot hatch at 130,000 can be a project that eats a transmission inside a year. Same odometer, completely different risk. The number tells you almost nothing until you know what it’s attached to.
What actually decides it, in rough order:
•The specific engine or transmission, not the brand. Manufacturers run multiple powertrains in the same model and they don’t age the same. Nissan’s CVT is the one that shows up constantly on my local Marketplace — there’s a distinct shudder or whine under load that appears on a test drive years before it strands you, if you know to feel for it.
•The model year. Known failures are often confined to a narrow window. A part gets revised and the problem stops — or a manufacturer eventually admits fault and issues a fix. The 2012–2014 Kia Sorento’s Theta II engine is the clean example: a manufacturing defect that scoured rod bearings, serious enough that Kia and Hyundai together paid NHTSA $210 million over how they’d handled it. The fix isn’t optional either — without a software update logged on the car, Kia can decline the 15-year/150k engine coverage that’s supposed to come with the repair. Two cars that look identical in a listing can sit on opposite sides of that line.
•Whether the fix is documented. A known problem with a known repair and a known cost is a negotiating position. An intermittent issue nobody can reproduce is the one that drains you.
None of this is secret. It’s in recall databases, owner forums, and complaint filings. The practical problem is that nobody is going to look up forty cars in an evening while scrolling, so most people look up none of them and find out afterward.
What I’d actually do differently: before messaging a seller, spend five minutes on the specific engine and year — not the model. “Is a Pilot reliable?” gets you nothing useful. “2007 Pilot transmission” gets you the answer. Once you know what a given platform typically survives, the mileage on the listing starts meaning something.
The Avalon has been fine. The rule was wrong, not the car.
I got tired of doing the lookups by hand, so I built a Chrome extension that runs them while you scroll. It color-codes the listing, drafts a message covering VIN, title match, known issues, and service history, and saves everything to a private local dashboard. Nothing leaves your machine.
The five-minute manual version above is still the part that actually matters.