What a strange experience... I had my annual performed earlier this month with no real issues to resolve. So, while I was feeling like I threw $600 down the sewer drain, I get a call from Tesla. The tech said the guys at HQ saw an error or two in the data collected during my annual and they want to check out my battery pack. So I sent the car away a few days later. The car was performing flawlessly when it left my home... I called today to ask what was wrong and when can I get my car back. I was told, "It's done now, I just finished washing it and your new battery pack is installed." So, long story short, there was some error code recorded for an issue that had in the past caused a section of the battery to fail in other cars. To prevent any future issues, Tesla just gave me a fresh battery pack at no charge. I am floored by this. The typical response to this type of an issue by other car manufacturers is to fix the problem for just long enough for the warranty to expire, at which time this all becomes my problem. I am very impressed and wanted to share this with other owners. Good work, Tesla!