As mysterious BMW fires continue, calls for investigation into possible causes grow Critics say the government auto-safety watchdog is failing to protect consumers.

Despite continued reports of parked BMWs bursting into flames, the government watchdog for automotive safety does not have an active investigation into possible causes.

Consumers have filed more than 90 complaints about the issue to the National Highway Traffic Safety Administration, including 30 since ABC News first brought the problem to the public's attention, prompting critics to call for a federal probe.

According to Jason Levine, the executive director at the nonprofit Center for Auto Safety, NHTSA is failing in its obligation to protect consumers.

"These BMWs have [had] these fire problems for a very long time," Levine told ABC News. "They've taken a very long time to respond to them. And it doesn't seem that they're getting to the bottom of the problem."

BMW insists that car fires can result from a variety of external reasons "unrelated to product defects." In 2017, a company spokesperson suggested several other potential causes of car fires, including a lack of maintenance, improper maintenance by unauthorized mechanics, aftermarket modifications, rodent nesting and even arson.

"In cases that we have inspected and are able to determine root cause," a BMW spokesperson told ABC News, "we have not seen any pattern related to quality or component failure."

Since ABC News' initial report in 2017, the company has issued four fire-related recalls affecting more than 1 million vehicles across various years and models.

The luxury automaker wasn't the only vehicle producer to take that step. Car manufacturers collectively have issued 62 parked-car-fire-related recalls since 2017. Just last month, for example, Hyundai and Kia recalled 168,000 vehicles for fire risk.

But while U.S. regulators have declined to investigate, BMW has faced scrutiny elsewhere. The company was recently fined $9.9 million by the South Korean government after its transport ministry determined officials had tried to cover up technical problems related to dozens of engine fires in diesel cars and moved too slowly to recall affected vehicles.

"I think what is particularly scary is that there's no [U.S.] watchdog out there that BMW is afraid of," Levine told ABC News. "The only thing literally keeping BMW's feet to the fire, forgive the pun, is going to be outside lawsuits. That's not how it should work."

In response to questions from ABC News, a NHTSA spokesperson said the agency is "in close contact with BMW in its oversight of automaker's recalls that involve a potential fire risk, and will take appropriate action if warranted."

Representatives for BMW have declined repeated requests for interviews, but the company has issued statements saying that "with approximately 4.9 million BMW vehicles on U.S. roads, fire incidents involving BMWs are very rare. ... BMW takes every incident very seriously."

ABC News and ABC-owned stations around the country have independently confirmed more than 50 reports of fires in parked BMWs that were not the subject of a fire-related recall at the time of the incident. Some of those owners have filed complaints to NHTSA, while others have not.

In October 2017, Laura Ohme said she and her two sons, Max and Eli, were forced to flee their San Diego, California, home when her 2014 BMW X5 ignited while it was parked and turned off in her garage.

"The explosion blew out [the] garage door," Ohme told ABC News. "Anyone really walking down the street could have been hit."

The family escaped unharmed, but the resulting fire destroyed their home. Fire investigators were able to pinpoint her recently purchased BMW as the source of the blaze.

"We're not the only family that has lost everything because of a BMW car fire," Ohme said. "Fix the problem."

Virginia Chamlee's said her 2005 BMW X5 ignited as it was parked and turned off in her driveway in Jacksonville, Florida, in July 2018. She reported the fire to BMW immediately but she said the company never came to inspect it.

"The woman I spoke with suggested that either I drove the car too much or I drove the car too little," Chamlee told ABC News. "I left the conversation feeling like nothing was going to get done."

And when Lynn Wrench received a recall notice for her 2011 BMW 328i xDrive in 2017, it arrived with a confusing caveat: "Remedy Unavailable." She said she called the company and spoke to a representative.

"He said they didn't have a solution yet," Wrench told ABC News. "And that would notify me when they did."

But more than six months later, while she was still waiting for a fix, her car ignited, she said, while it was parked and turned off in her hometown of Colgate, Wisconsin. Although the vehicle was unsalvageable, BMW only offered Wrench a $3,000 rebate on a new or pre-owned BMW, reimbursement for a rental car and an additional $1,500 settlement -- a deal that came with one major stipulation.

"They wanted me to sign a non-disclosure agreement, so I would't even be able to talk with you about this. Or anybody," Wrench said. "Why would I do that?"

Wrench isn't the only BMW owner who received a recall notice bearing the words "Remedy Unavailable."

James McManus of Temple, Texas received a recall notice for his 2011 BMW 550i in June 2018, advising him that the company was "not ready to perform this recall on your vehicle," but "BMW recommends parking your vehicle outdoors until repairs have been performed."

It was too late. His BMW had already ignited while he said it was parked and turned off in his garage two years prior, damaging his home and forcing him and his then-pregnant wife to relocate during repairs.

BMW said it was "out of abundance of caution" that it made that recommendation and insisted that the company "worked diligently to secure an adequate supply of parts so that affected vehicle can be fixed as quickly as possible."

Joseph Santoli, a New Jersey-based attorney who's sued BMW in the past, told ABC News he has been contacted by many angry BMW owners exploring their legal options after reporting that their parked cars caught fire.

He slammed the automaker for "dragging their feet" and urged federal regulators to make the issue a priority before it turns deadly.

"NHTSA needs to bring pressure, as much pressure as they can bring on BMW," Santoli said, "to repair recalled vehicles as a quickly as possible so that these fires don't happen anymore."

The consequences can be devastating. Bill Macko, a subject of ABC News' original report, was a loyal BMW customer until his 2008 BMW X5 suddenly and inexplicably caught fire in 2015 as it sat parked in his garage in Olney, Maryland.

The ensuing blaze leveled his home, and more than three years later, he and his wife are still displaced.

"It's turned everything upside down," Macko told ABC News. "In all honesty, it makes you angry. And I don't know if I could ever get rid of the anger. It's just so frustrating to realize that three years of your life have been basically put on hold."

ABC News' Shannon Crawford, Emily Ruchalski and Jinsol Jung contributed to this report.