Hello, a week ago I dared to change the heat exchanger so that the car in a workshop would not be an economic total damage. So without the expansion of the entire cockpit, the steering column and other attachments. Maybe I can give one or the other by my experience a working heater again. Unfortunately, with the car also no flushing with high pressure helped, because many small and large particles had accumulated exactly in the heat exchanger and this was not possible. There was no improvement after several rinsings. In the procedure shown only the lower lining in the footroom has to be removed and to the right of the accelerator the cover. In addition, a nut from the air channel for the feet to get better. Then 3 screws that blind the pipes. If someone has detailed questions, I am happy to be available. I recommend to use high quality clamps, as this procedure otherwise the risk for a wet Teppi Since there are at least 2 layers of plastic between the feet and the pipes, I see no danger of hot water on the feet or legs. The hose used is a cooler hose, suitable as a meter product, exactly suitable. I deburred the pipe ends with a file. Dimensions inside: 19mm Dimensions outside: 27mm The car is driven daily and until now everything is dry and the heating works great.