A new survey of over 2,000 people reveals a costly and preventable pattern: buyers who skip basic due diligence are paying for it. Sometimes costing $3,000 or more. Hidden in the data is a more unsettling story than individual oversight. It points to a repeated issue in the used car market, where buyers end up thinking that sellers know more than they disclose and buyers absorb the consequences.

Of the respondents who experienced unexpected major repairs within two years of purchase, most discovered problems within the first month of ownership, well before normal wear and tear could explain them. Nearly half felt their seller had withheld known issues. And 62% had never run a vehicle history check before handing over their money.

Quick Insights:

• 24% - spent $3,000+ on repairs
• 62% - skipped the VIN check
• 58% - found issues within 1 month
• 48% felt the seller withheld info

The $3,000 Mistake You Could Have Avoided for $40

Among the respondents who reported repair costs, more than half spent over $1,500 within the first two years of ownership. A quarter spent over $3,000, which could match or surpass the savings that drew them to the used car market in the first place.

Repair costs within first 2 years

53% spent more than $1,500 on repairs within 2 years

24% exceeded $3,000 often erasing the savings from buying used

The VIN check gap

Here’s where consumer math becomes striking. Of the buyers who faced costly repairs, 62% had skipped a vehicle history (VIN) check entirely before purchasing.

62% did NOT check VIN before buying

38% DID check VIN before buying

Among those who did check a VIN report, seller disclosure rates were notably better. Informed buyers either screen out problem vehicles earlier or sellers are less likely to conceal known issues from buyers who clearly know what to look for.

Used Car Buyers Are Buying Someone Else’s Problem

When issues emerge within days or weeks of purchase, it’s difficult to attribute them to the new owner’s driving habits or maintenance choices. The timing data in this survey makes a strong case that many of these repairs were pre-existing conditions.

How quickly did repairs emerge?

Disclosure Problems

Nearly half of affected respondents (48%) felt their seller had not fully disclosed known issues before the sale. Only 35% felt completely informed going into the purchase. This isn’t a fringe complaint; it’s a shared experience of some used car buyers who end up with surprise repair bills.

Not a Private-Seller Problem, a Market-wide Problem

It would be easy to assume that private sellers are the primary culprits and that buying from a dealership offers meaningful protection, but the data says otherwise. Among respondents who faced surprise repairs there was nearly an even split with 51% buying from a private seller and 49% from a dealership.

Sellers in the used car market will almost always know more about a vehicle than the buyer standing in front of them. That’s not a matter of individual dishonesty, it’s how the market is structured. Buyers can work to close that gap by taking deliberate steps to get all of the information they can before signing.

Most Common Issue Types

Engine and transmission problems together account for 58% of all issue mentions, and they are also the most expensive categories to repair, directly driving the high-cost tail observed in the repair cost data.

Types of issues experienced: Here are the most common issues reported by respondents:

*Note this was a multiselect question so percentages will not add up to 100%

Who Gets Hurt Most

Buyers the most at risk share a common profile: they skipped the VIN check. Whether they found their vehicle on Facebook Marketplace or Craigslist or through a friend or family member, or at a dealership, the data shows that regardless of where they bought, who they bought from made no difference to their odds of ending up with a costly repair bill

The 51/49 split between private sellers and dealerships among those who experienced costly repairs makes that point clearly. What separates higher-risk buyers from lower-risk ones isn’t where they bought, but what they did before signing.

What buyers wish they had done differently:

*Note this was a multiselect question so percentages will not add up to 100%

What the Smart Buyers Should Do

These are not finger-wagging recommendations. They’re the actions that buyers in hindsight most wished they had taken, grounded in what the data shows correlates with worse outcomes.

Run a VIN check — every time, every seller type. The 62% who skipped it paid a steep price. The cost is trivial against even the lowest repair tier in this survey.

Budget for a pre-purchase mechanic inspection. At $100-$150, it was the #1 thing buyers wished they’d done. A mechanic can surface the engine and transmission issues that account for the most common — and most expensive — repair categories.

Treat fast-emerging issues as a red flag, not bad luck. Problems surfacing within days or weeks of purchase are rarely coincidence. If a car develops issues quickly, the seller almost certainly knew.

Don’t assume a dealership means disclosure. A 51/49 split between private sellers and dealerships among affected buyers is the clearest evidence that channel alone doesn’t protect you.

Methodology

This study is based on a survey conducted by Bumper.com in April 2026, drawing responses from 2,011 visitors who were actively looking up vehicle history reports at the time. Respondents were first asked a screening question: whether they had experienced unexpected major repairs within two years of buying a used car. Those who answered Yes were routed to follow-up questions covering repair timing, issue type, purchase source, costs, and seller disclosure. Response counts vary across questions due to optional fields. As with all self-reported survey data, results should be interpreted with that context in mind.