simple and straight, if no cash or no cleared funds in your account, do not release the car!
on the same note, also dont go to buy car alone with all cash, not everyone is seller but can be ready to rob your money instead of selling you car!!
it has happened here in UK few times, some guys advertise car at attractive price, ask people to come and collect at given area pretending its their house and waiting outside, then rob you at knife point and run away!