i am trying to buy a car with my bitcoin without convert my bitcoin to Fiat if its possible suggest me any idea.
From which country are you bro? It is not that easy to look for car dealers that accept bitcoin as payment. You will be having a harder time since it is very difficult to look for cars online. If there were cars sold online then it might become easier for you. But since cars are actually sold on hard stores then I advise you to convert your BTC to fiat first.