Well , we are living in Cyprus . The island is very hot and dusty and I dont think that a solution is to switch off the air con. Also the manufacturer does not fit cover under the engine. After visiting the garage for the first service and did mention the problem they were unable to explain the problem instead they reasure that there is no mechanical problem with the vehicle (they compare another vehicle in dusty parking -does the same thing).I requested a solution because my wife feels very embarased driving the vehicle with this condition. they said they will come with a solution through the manufacturer, FRANCE ,in order to cover it the guarantee. I beleive the solution is to put a cover under the engine. still waiting for their answer, if not i will sell the vehicle. I have audi ,my previous was a nissan, my wifes previous car was a toyota starlet and never faced such a problem with neither vehicles.