Update June 11: NHTSA issued a statement saying that it has found no issue with Model S suspensions, and that it was satisfied with an amendment to Tesla made to its goodwill agreement.
After a blogger stirred up an Internet clamor around one owner's Model S suspension failure, Tesla gave a strong response on its blog, asserting that there is no National Highway Transportation Safety Administration (NHTSA) investigation into the issue, and there is no defect on Model S and Model X suspensions. However, the Model S owner denies part of Tesla's response as to where he drove the car.
Along with the suspension failure, Tesla was accused of having owners sign a goodwill agreement for repairs that held them to confidentiality in the matter, preventing them from exposing problems to the NHTSA. The Wall Street Journal cites "a person familiar with the matter" who said that aspect of Tesla's goodwill agreement is being revised.
The issue arose when Model S owner Pete Cordaro wrote about a failure of his front suspension on the Tesla forums. The issue was conflated with other Tesla stories by Daily Kanban writer Edward Niedermeyer, alleging widespread problems and an NHTSA investigation.
On its blog, Tesla took issue with Niedermeyer, pointing out bias in a blog he wrote in 2008 called "Tesla Death Watch".
Tesla's post also says that Cordaro "lives down such a long dirt road that it required two tow trucks to retrieve the car." However, Cordaro writes on Tesla forums that the road to his house is paved, and he only ever had his Model S on a dirt road once.
And while Tesla claims that it would never ask owners not to talk to NHTSA about safety issues, an apparent copy of its goodwill agreement posted online includes the sentence, "You agree to keep confidential our provision of the goodwill, the terms of this agreement and the incidents or claims leading or relating to our provision of the goodwill."
Tesla's blog post says that the owner, Cordaro, was not constrained by the goodwill agreement he signed in reporting the suspension failure to NHTSA, and notes that while NHTSA is has received the complaint, has not opened an investigation into the issue.