Takata's stock is suddenly deflating like a used airbag.

Hammered by safety and emissions scandals, investors are running scared and abandoning auto manufacturing giant Volkswagen AG and industry supplier Takata Corp.

And the exodus has only exited this week in the wake of new problems for the two companies that have raised questions about how VW and Takata will operate going forward. Some analysts are questioning whether VW may have to sell off some of its dozen brands while questions are mounting about whether the Japanese supplier can survive at all.

Takata was hammered this week by one of the largest fines ever levied by the National Highway Traffic Safety Administration, while VW saw new allegations of cheating on emissions tests by the Environmental Protection Agency.

The crisis at VW began on September 18^th, when the EPA first accused the German giant of cheating on emissions tests involving 482,000 diesel vehicles sold in the U.S. VW quickly acknowledged the problem and revealed it had used a “defeat device” in the programming of 11 million vehicles sold worldwide using its small EA 189 turbodiesel engine.

That set off a flurry of new investigations, including a criminal probe by the U.S. Justice Department, and another in Germany. American courts are now trying to sort through over 300 lawsuits targeting VW.

Porsche is now linked to VW's scandal - a potential problem for CEO Matthias Mueller.

But things got notably worse this week. The EPA accused the company of cheating on emissions with vehicles using a larger, 3.0-liter diesel. That led the maker to order a new stop-sale of models sold under the VW, Audi and Porsche brands. While Volkswagen officials denied the EPA allegations, they revealed an internal investigation uncovered “irregularities” involving 800,000 other vehicles, some gas-powered.

(VW finds new emissions “irregularities. Click Here for the latest.)

That has led to yet another sell-off of VW shares, the stock on Thursday dropping below the $100 mark for the first time in over five years. It had peaked last March 15^th at $255.20, and stood at $167.80 on September 17^th, the day before the EPA sent investors racing for the exit.

How much further might VW tumble?

“Public trust is at stake here,” said European Union executive commission spokeswoman Lucia Caudet said on Wednesday.

The fact that a major Porsche product, the Cayenne SUV, is now potentially involved in the emissions scandal could tarnish the reputation of Matthias Mueller, the former Porsche chief who raced in to replace Martin Winterkorn as Volkswagen CEO shortly after the first revelations of emissions cheating, warned Michael Hewson, a senior analyst with brokerage firm CMC Markets.

Takata stock has been on a similar slide in recent weeks as the safety systems supplier sees long-time customers flee and federal regulators force it to accept a costly consent agreement. That deal will force Takata to accept an independent monitor and speed up the production of replacement airbag inflators. If it doesn’t comply it could see a $70 million fine raised by NHTSA to $200 million.

But that may pale compared to the business it is losing. Mazda is the latest automaker to say it will no longer purchase Takata airbag systems using the volatile and suspect chemical ammonium nitrate for its inflators.

While no formal cause has been found, many experts – such as Clarence Ditlow, Director of the Center for Auto Safety – believe that chemical can break down over time, leading to the sort of airbag misfires now linked to at least eight deaths and 98 injuries.

The majority of those incidents have involved vehicles sold by Honda. The third-largest Japanese automaker and Takata have been closely linked through the Japanese keiretsu system. But those ties are about to be severed, Honda announcing it will no longer buy Takata inflators.

“We have become aware of evidence that suggests that Takata misrepresented and manipulated test data for certain air bag inflators,” Honda explained on Tuesday. “Honda expects its suppliers to act with integrity at all times, and we are deeply troubled by this apparent behavior by one of our suppliers.”

With Mitsubishi warning it may also switch suppliers, Takata stock fell by 25% in Asian trading on Thursday, to $889 a share. That’s down from a peak of $1,848 last January. Surprisingly, the supplier had weathered its own storm reasonably well until this week, but investors finally seemed to read the tea leaves as customers like Honda began calling it quits.

Airbag systems represent barely a third of Takata’s total business. But the exodus could impact other business lines. And along with the NHTSA fine, Takata is facing its own legal problems, including a criminal probe.

(Takata hammered by NHTSA. Click Here for more.)

That is raising questions about just how it will fare long-term, some analysts warning it may eventually be broken up, sold off, or forced to declare bankruptcy to put a framework around its financial problems.

(Click Herefor more on Honda’s decision and the impact Takata had on its earnings.)