The important thing was that was in the description that hot air must be passed through the evaporator at first, so he dries completely and then to run the circulating air without activating the air conditioning, so that no condensation forms on the evaporator. So could undiluted up to the evaporator and kill all the disinfectant. Is the evaporator iced up, the disinfectant is not even ran to the metal. When the heater is wet, the disinfectant is diluted so that it no longer works. The evaporator must be dry throughout the Desinfekionsvorgangs. The can comes directly under the glove compartment and not like many other letters in the rear. It is then taken directly from the circulating air and fed to the evaporator. During disinfection, the air is to cold. The chemical smell of solvents is already after 24 hours history. In another company he stayed for 14 days hartnächkig. That was not so nice. I will therefore always assume this means immediately. Strong buy recommendation!