Kia and Hyundai (HYMTF  ) are facing class action lawsuits after a viral TikTok trend revealed how easy it is to steal some Kia and Hyundai models, leading to a wave of car thefts. The so-called "Kia Challenge" shows that design flaws make it possible to steal one of these vehicles in under a minute.

There have been suits filed by car theft victims in several states, including Iowa, Wisconsin, and Ohio. The plaintiffs allege that the carmakers failed to disclose that design defects make the vehicles especially vulnerable to theft.

Thieves are able to steal the vehicles quickly by accessing the ignition through the steering column and turning the engine on using a screwdriver or USB stick.

While low-end models are vulnerable, most models are safe thanks to their immobilizer, a device that prevents the vehicles from starting unless a key is present. The technique also only works on vehicles with steel keys, not key fobs and push-to-start.

"While no car can be made theft-proof, criminals are seeking vehicles solely equipped with a steel key and 'turn-to-start' ignition system," a Kia spokesperson told reporters, adding that key fobs make vehicles "more difficult to steal."

According to the Insurance Institute for Highway Safety (IIHS), 96% of vehicles from other brands included immobilizers by 2015, but Kia and Hyundai still only offered the devices in 26% of their models.

These vehicles have been a target for thefts for years. Viral videos featuring the theft technique started popping up as early as 2021, but the trend really took off this summer on TikTok. According to Kia and law enforcement, there was a significant jump in Kia and Hyundai thefts in the Midwest this summer.

Charlotte, North Carolina, reported that thefts of Kias and Hyundais in the city were up 346% in June. Detroit, meanwhile, saw its Kia thefts double in June from 11 to 23, before skyrocketing up to 111 Kia thefts in July.

Hyundai has acknowledged that its vehicles "have been targeted in a coordinated effort on social media," and the carmaker is offering an anti-theft kit in the form of a steering wheel lock to prevent these types of thefts. Kia says it isn't offering any added security measures. The Hyundai Motor Group is the parent company for both brands.

"Offering [a security kit] and then charging them to install it is not acceptable," said Jeffrey Goldenberg, an attorney representing plaintiffs in a class action in Ohio.

Despite the fact that both companies have acknowledged the flaw, neither has offered to fix the issue or compensate consumers, according to the Iowa class action. Hyundai says that all of its vehicles "meet or exceed Federal Motor Vehicle Safety Standards."