Car purchase of private brakes must be renewed !

Hello, I have here a question: I bought from private a seventeen year old Fiat, the car has even more than a year TÜV. This was indicated as ready to drive in the advertisement. Before the purchase took place a short correspondence, in which I was assured that the car would drive in any case still a year. When I bought I drove test and it was pointed out to defects like worn tires. I do not know myself with cars and bought the car. After three weeks I let the vehicle look at in a workshop. Brakes in the rear broken, air filter, tires may no longer be driven.. Car was sold under exclusion, with contract that includes this clause. Can I withdraw vol purchase contract?