I have read about many folks getting the drive unit replaced and now it has happened to me. It makes me wonder how common of a failure this really is? It is sounding really common which has me concerned for total lifetime situation. (Yes I know it's under a long warranty) Survey below for raw numbers. It would be interesting to provide details if you have had it replaced: Model: S Approx Miles/kms: 37,000 mi Trigger for replacement: Whine like gear noise on acceleration.