I would think its a very clear case. The dealer sold you the car on the basis it was a 2009 model. It was advertised as such and the price you paid reflected that.
If indeed it is 2007 then its misrepresentation, clear and simple. Give the dealer the opportunity to do something about it and make it clear that if he doesn't you will go straight to Trading Standards. Then do it.
and welcome by the way!
