Never pay before signing the sales contract and receiving all documents and vehicle keys.
We generally recommend to pay cash rather than arranging money transfers in advance.
Do not make any deposits! Down payments are not customary when dealing over the Internet and there is a risk that you are the one to chase your money when the car is not delivered. This is especially tricky in cross-border dealings.
The normal procedure is delivery versus payment, i.e. you pay when you receive the vehicle and vehicle certificates. This is the safest way for you to settle the transaction and enjoy the pleasure of driving your new car.