The Tesla Model X falcon doors have been a major source of problems for owners.

Tesla is being hammered again for quality woes as a growing number of owners complain about the new Model X battery-electric sport-utility vehicle.

And after soaring to recent highs, the California carmaker’s stock is tumbling in the wake of a new report by Consumer Reports magazine spotlighting issues such as the frequent failure of the unique “falcon doors” on the Model X. The magazine noted a variety of other issues that have left customers increasingly frustrated.

“Tesla message boards are already swelling with complaints from Model X owners regarding balky doors, interior trim-piece tolerances, paint-spray quality, malfunctioning second-row seats, sheet-metal panel gaps, and climate control issues,” Consumer Reports said in website post.

It’s the latest in a series of critical articles posted by the non-profit publication – and marks a sharp reversal in its position on Tesla products. Barely a year ago, CR declared the Model S battery sedan the best vehicle it ever tested, but soon after it reported on numerous quality issues with that vehicle and lifted the sedan’s coveted “Recommended Buy” endorsement.

Tesla CEO Elon Musk insists the company is intent on delivering industry-leading quality.

Consumer Reports is by no means alone. Owner websites have been abuzz with reports of problems, and journalists testing the Model X have also sounded alarms. The SUV’s unusual, vertical-opening falcon doors seem to be one of the biggest sources of complaints, owners frequently reporting that they won’t operate properly.

(Tesla issues first recall for new Model X. Click Here for details.)

Tesla reportedly pulled hundreds of early Model X SUVs from delivery to attempt to fix the problem, and it’s unclear if those being built now are operating any better. But the maker issued a statement in response to the Consumer Reports article insisting, “We are committed to making the world’s most reliable cars.”

“While we have seen some issues with early Model X builds, the issues are not widespread,” the statement declared, “and we are working closely with each owner to respond quickly and proactively to address any problems. We will continue to do so until each customer is fully satisfied.”

Tesla recently filed suit against the Swiss company that designed the original hinges for the Model X falcon doors and noted it subsequently developed its own hinges.

Despite Tesla's ongoing quality issues, demand for the new Model 3 remains strong.

Despite the continuing quality and reliability issues, owners do note that Tesla has been extremely supportive, quickly responding to complaints and making repairs under warranty. The challenge for some owners is the relatively low number of Tesla dealerships around the country compared to more mainstream manufacturers. In some cases, owners report, that has meant having vehicles flatbedded to another state for repairs.

(Click Here to see how a surge in lithium prices could stymie the market for EVs.)

Along with the door issue, one of the most frequently reported issues is a double-vision problem caused by the massive Model X windshield which rolls into the roof of the SUV. Intended to provide more visibility than a traditional windshield, it can cause an oncoming car’s headlights to appear as if there were two approaching vehicles.

Fit-and-finish issues, ranging from poor paint quality to large gaps between sheet metal panels, were also reported, as were issues with the climate control and auto-parking system on the Model X.

Technical problems with any new vehicle are not uncommon, but the breadth of the issues with the Model X, especially in the wake of continuing quality and reliability issues on the Model S, have given analysts and investors pause.

“Statistically speaking, this car is more likely to have problems than the average vehicle,” cautioned Consumer Reports spokesman Jake Fisher.

The influential publication’s report sent Tesla shares plunging $6.51 on Tuesday, to $247.37. The company’s stock has been settling back since reaching a high of around $260 a share following the debut of the new Model 3 sedan on March 31^st, but it is still well ahead of the valley Tesla fell into earlier this year.

The debut of the Tesla Model 3 was greeted with advance consumer orders of more than 300,000 vehicles, even though the maker doesn’t plan to deliver the first of the battery sedans until late 2017. And observers question whether it will meet that timetable considering the Model X was about two years late to market.

(Ford cuts price, rather than boosting range, with updated Focus EV. Click Here for the story.)