Hi Keith, I also experienced diesel exhaust fumes in the cabin of my 2007 GV 2.8 CRD but it wasn't the Webasto in my case. It came from where the EGR tubing's connected to the exhaust manifold at the rear of the engine and also where the other end of the tubing's connected to the EGR valve itself. I hope your garage has found the right problem. These fumes are really bad. JohnE