This week, Consumer Reports has released its Annual Auto Reliability Survey, and the results are nothing short of surprising. In fact, cars that the consumer watchdog trumpeted just a few months ago have come under fire as drivers describe day-to-day life with their new cars, sometimes with less than impressive results.

While virtually every new car is thoroughly gone over when new, the group’s reliability survey is the one that separates the wheat from the chaff. All the expensive options and trim levels are subjected to everyday driving, and are forced to prove their toughness against cold starts, carloads of kids, hot days, rain storms, snow storms, and nearly everything in between.

But while the list is certainly a wakeup call for manufacturers, it’s by no means a black spot. Often, automakers are penalized for rolling out new models, as the unproven powertrains and infotainment systems tend to be problematic for early buyers. But as the models mature, and automakers work out the kinks, they tend to be rewarded by a higher ranking.

So with that in mind, here are the six automakers who took the biggest plunge in the 2015 Consumer Reports Annual Auto Reliability Survey.

1. Acura

Honda’s premium brand has been selling great as of late, with sales up 6.3% through September. But the success comes at a price: The new RLX and TLX models may be flying off the lots right now, but the first-year models are having plenty of teething issues. Because of this, Acura slid a full seven slots, from 11 down to 18. If it can fix the electronics and transmission issues that customers are complaining about, expect the brand to have a stronger showing in 2016.

2. Cadillac

As it continues to struggle to find buyers, the last thing Cadillac needs right now is some bad PR. Unfortunately, General Motors’s flagship brand fell seven spots – from 18 to 25 – largely based on its troublesome Cue infotainment system. Cadillac isn’t taking the news lightly, however, with a spokesman telling Automotive News, “Cadillac’s product development experts are analyzing this data, along with other information we have [from] owners, as part of the ongoing elevation of our product portfolio,” and adding, “There are significant upgrades to 2016 models in production now, including enhancements to CUE such as faster and more powerful system response and the inclusion of Apple CarPlay.”

3. Porsche

Porsche scored high in Consumer Reports’ new car testing, with the Porsche Macan ranking as one of the highest-rated vehicles of the year. But as is the case with high-end luxury cars, long-term reliability isn’t always a top priority. Because of complaints largely from Macan and Cayman owners, Porsche slid five spots this year, from nine to 14. 

4. Infiniti

This summer, we drove the Infiniti Q50 S, and we loved it. With strong performance, a truly great interior, and a top-notch infotainment system, our Micah Wright said, “It may not have the racing pedigree of an AMG or the ferocity of an M-series, nor can it compete with the hulking supercharged V8 found in a Cadillac CTS-V, but that’s not what Infiniti is about. The Q50 S never pretends to be something it isn’t, and for that, we’re grateful.”

Like Acura, it seems like Infiniti owners’ biggest gripe is the infotainment system, and as a result, the brand slid from No. 20 to 24 this year. Once Nissan’s luxury brand gets the bugs worked out, we expect it to climb right back.

5. Honda

For 2015, Honda debuted a redesigned Fit, a face-lifted CR-V, and launched the HR-V crossover. For 2016, an updated Civic, Accord, and all-new Pilot are on the way. While that’s sure to bring buyers to Honda dealerships, it also means plenty of growing pains for all these new models. Honda slid from No. 4 in 2014 to 8 in 2015. Until all these models mature, Honda may be in for a rocky year or two on this list.

6. Tesla

The biggest news from Consumer Reports came from an automaker that didn’t even make the list. After famously breaking the group’s ratings system this summer, the consumer watchdog announced that it could no longer recommend the groundbreaking EV due to a number of reliability issues. Customers cited a number of problems, from sunroof leaks, to powertrain issues to batteries with charging issues. After CR issued its statement, Tesla’s notoriously fickle stock plunged 10% before closing at $213.03. But Elon Musk and company have rarely shied away from a fight – there’s a good chance the company will tackle the reliability issues sooner rather than later.

Like classics? It’s always Throwback Thursday somewhere.

Follow Derek on Twitter @CS_DerekS