Consumer Redressal

My name is renish joseph.i bought a hyundai eon era plus star dust car on 27/04/2015.I am writing this letter regarding a serious issue with my eon car.Actually i have already made numerous complaints in this regard.But i did not get any satisfactory response from you as well as the dealer(s s hyundai,mavelikara).Whenever i drive the car with the windows closed there is this noise from the engine.I do not know whether it is coming from the engine or somewhere else.The car almost sounds like a tractor .And i found it very embarrassing and irritating.I brought it to the notice of the dealer several times and they are saying that this is common with all EON cars.If what they are saying is true,its a manufacturing defect and the company is liable to replace the car or rectify this issue.Last time when i made the complaint they made me believe that this is a common problem and they also made me sign the customer satisfaction letter.