One thing that comes to mind that I have seen before is scammers copying an advert for a car that is/was for sale and then putting it on eBay/Pistonheads etc with a much lower price.
The idea being that they will ask you for a deposit before you see the car and keep it as they don't even have the car or like what happened to another member on here a while ago which was he paid in full without even seeing the car as it was such a good deal and arranged to have the car delivered, ...the car never was delivered (luckily he managed to get his money back via the bank).
Link: http://www.350z-uk.com/topic/94916-warning-possible-scam-on-ph05-rod/
Just be careful Chris and definitely don't exchange any money, bank details etc without seeing the car/V5's etc.