I had my front air struts replaced with the 77-C update in April of this year but the rattle returned about 1,000 miles later. Subsequent trips to the SC for the issue didn't produce any result as the technician riding along always claimed not to be able to hear the rattle. (I guess they think I'm lying about it? Are they all deaf? Not sure.) Growing tired of the issue, I scheduled a mobile appointment to get a different set of ears. The mobile tech heard the rattle and had the SC order parts based on his evaluation of the noise. A month passes and appointment is delayed because parts did not arrive. On the morning of the repair appointment, the SC made me take a technician on YET ANOTHER ride along to confirm the noise. Noise was confirmed. They keep the car overnight to do the work and the next afternoon I am set to pick up.
Upon pick up, I am informed that they didn't do anything to the vehicle and that the rattle is "normal". The SC advisor said that the rattle is simply - and I quote - a "design characteristic" of the Model S. They did not deny that the rattle existed, the position now is that it's normal. The service invoice indicates that they drove another Model S with a similar VIN range, confirmed the rattle in that car, and so, the rattle is normal in my car. I told them that makes no sense whatsoever and that means the rattle is clearly the result of a design flaw in the vehicle.
I asked then what parts were ordered. No answer. Why were parts ordered if the rattle is normal? No answer. Why did the front suspension not rattle when the car was new? No answer. What about when the 77-Cs were first installed? Why no rattle then? No answer.
I don't think that they actually know how to fix the rattle and this will be the new answer we receive when the issue is not resolved by replacement of the air struts with the 77-Cs. This experience has really shaken my faith in Tesla and their commitment to customer satisfaction. I'll probably move back to Audi/Porsche at this point. I've had so many issues with this vehicle in the past 1.5 years (including all the common ones - yellow borders, failed DRLs, etc.) and this, I think, is the final straw for me.