Tesla’s best-selling Model 3 sedan lost two designations from Consumer Reports after the company made changes to the car’s automatic braking and front collision warning systems.

The car also was stripped of its designation as Top Safety Pick+ from the Insurance Institute for Highway Safety.

The moves came after Tesla announced that, as of May 1, its Model 3 and Model Y SUVs replaced the radar based system it used to detect obstacles with a camera-based system it dubbed “Tesla Vision.”

“These will be the first Tesla vehicles to rely on camera vision and neural net processing to deliver Autopilot, full-self driving and certain active safety features,” said a statement that Tesla posted on its website. Tesla did not respond to a request for comment about the changed ratings designations.

The change in technology prompted the US federal safety regulator, the National Highway Traffic Safety Administration, to drop the cars’ listing as having automatic braking or a front collision warning system. And that, in turn, prompted Consumer Reports to change its rating on the Model 3.

“To be considered for a Consumer Reports Top Pick, a vehicle must be recommended and have standard front collision warning and automatic emergency braking with pedestrian detection,” said Consumer Reports in a posting on its site. Without those features the Model 3’s overall score dropped to 75 from 78, although it retained its “recommended” status.

The Tesla Model Y—which was not a recommended vehicle—drops from 50 to 47.

Jake Fisher, senior director of Consumer Reports’ Auto Test Center, said he was surprised that Tesla would do away with the radar.

“In general, more sensors are more helpful,” he told CNN. “But I cannot make a judgment as to whether this is better or worse.”

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He said it is disappointing and unusual for an automaker to drop a safety feature. “I don’t understand why they would, unless it’s another reason, like parts availability,” he said.

Many automakers, including Tesla, have been struggling to get enough computer chips to build their cars.

Fisher said the change by the federal agency prompted Consumer Reports’ actions, not any of its own testing.

“NHTSA only includes check marks for the technologies on a vehicle model that have been either verified by NHTSA or reported by the vehicle manufacturers as meeting NHTSA’s performance criteria,” said a statement from NHTSA about its action. “We removed the check mark because we have no test results for Tesla’s recent changes.”

The IIHS said it plans to conduct tests soon on the new camera-only system, and that it is possible it will restore the rating.

“Tesla informed us directly of the changes they were planning, and we let them know we’d need to test the camera-only system before extending the Top Safety Pick+ award to vehicles with that system,” said IIHS spokesman Joseph Young. It still lists the earlier versions of the Model 3 as a Top Safety Pick+. It has no rating on the Model Y.

Tesla delaying Model S “super car”

In a tweet earlier this week, Tesla CEO Elon Musk said Tesla was pulling the plug on his promised Tesla Model S Plaid+ super car about a year before it was expected to go on sale.

Tesla still plans a “Plaid” version of the car. In a tweet on Sunday, the Tesla CEO said that Plaid+ was being canceled because there was “no need, as Plaid is just so good.”

But Tesla had talked about the Plaid+ being able to go more than 500 miles on a single charge, while the standard Plaid version is advertised as being able to go 390 miles. Both versions were to have three motors, more than the two in other top-end versions of the Tesla. And Tesla said both Plaid and Plaid+ would be able to accelerate from 0 to 60 in about 2 seconds, making them the fastest production cars ever.

The Plaid+ was set to be $30,000 more expensive than the standard Plaid version, costing just under $150,000. All the versions of the Model S and the high-end Model X SUV together represented only 11% of Tesla sales last year, with the lower-priced Model 3 sedan and Model Y SUV becoming the mainstays for the company. But the Model S and Model X likely have better profit margins than the Model 3 and Model Y, making them important models for Tesla’s lineup.

Trouble for Tesla?

The delays in the new versions of the Model S and Model X, and the dropping of the highest end version of the Model S could point to some troubles at Tesla.

“This is not the news that Wall Street wanted to hear,” said Daniel Ives, tech analyst at Wedbush Securities. “At the surface the excuse makes sense, but it also feels like ‘The dog ate the homework.'”