"Online Scammers: try not to sell your car online as there are lots of scammers online. Sometimes the seller doesn’t get the money before him actually ship the car to the buyer. It’s really a risky business online, so try not to sell it online. "
This is a good tip emad, but I must say that there are many reliable websites that can help you with buying/selling used cars. So, we should not ignore the possibilities that the Internet provides.