Here you can find information on how to report this crimeMetropolitan Police Service - Fraud Alert
It helps if you have copies of all documentation (emails etc)

It would also be helpfull if you could post the advertisement for the car on here.

The website was shut down because it was reported...He will set up a new website in the next couple days.If we know where and what he advertises we can shut them down as fast as he sets them up.