Help! My A3 Sline is now 6 Months old and in my opinion has a developed a knocking noise which seems to come from the passenger side rear. I have takem my car to the dealers twice now only to be told the under tray was loose and they have tightened it up. However it does not seem to have cured it. I can only describe the noise as similar to running the car over chevrons constantly, causing a low frequency knocking. The dealer thinks I'm mad, but am I. Has anyone had or got the same problem?
