Ford have announced that third-quarter results will fall short because 45,000 cars are stuck in production due to a lack of parts, the market decided to wipe 12%, or $7billion, off Ford’s valuation on Tuesday, the largest single-day decline since 2011.

That’s on the back of the 95,000 GM was stuck with last quarter. Both companies see this as a passing worry, saying that shortages of key components like microchips should soon be over and they expect to sell stranded vehicles when sufficient supplies arrive.

But as industry pressures mount, optimism sounds increasingly off-key.

Adding to worries are two details in Ford’s announcement: supply costs rose $1 billion higher than anticipated, and its stranded vehicles are particularly profitable models.

There are very few solutions to an inflation-driven cost increase problem. They can try to up the proportion of high-end, more-profitable cars sold, or they could raise sticker prices across the board. But if shortages of specific parts for higher-profit vehicles persist, the situation is out of their control.

Increasing sticker prices will also get harder as interest rates rise and auto loans become more expensive. The average monthly repayments increased nearly 15% year-over-year to $667 in the second quarter, according to Experian. And prices are already stratospherically high – new vehicle prices keep setting records, up 10.8% year-over-year in August, according to the Blue Book.

If automakers cannot deliver on more-profitable cars or keep raising prices, inflation will inevitably eat into results.

Wall Street expects Ford’s operating profit for the full year will come in at $10.7 billion – below company expectations of $11.5 billion or higher. GM’s third-quarter results will be a key test of whether carmakers really can bounce back from these surprise shortages. Even if it hits the mark, warning signs are blaring.