Hi everyone I have come across an A3 DSG Tdi for sale with 70k on the clock, it comes with FASH with a rebuilt gearbox and a replaced mechatronic. My question is how common is this fault and does it return? What causes the mechatronic to fail? I have googled this and found countless problems with dsg and mechatronic issues on VWs and Audis which is kind of putting off from buying this car. Should I have anything to worry about if it has been replaced?