Chris Martin knew he needed a bigger car as the birth of his fourth child approached, but he and his wife were already $14,000 underwater on their two vehicles.

So the couple proposed an unusual two-for-one deal with an Atlanta-area auto dealer in 2020: trading in both of their vehicles so they could afford a three-row Ford Explorer. Their total loan after factoring in negative equity, a service contract, fees and other costs ballooned to $66,000 on the $49,000 Explorer.

Despite a lot of progress on the debt, he feels uneasy. “I don’t want to be paying interest on cars that I don’t even have anymore,” said Martin, a 36-year-old data engineer.

The build-up in negative equity — or the amount that debt exceeds a vehicle’s value — is rattling consumers and raising alarms within the industry.