We do rather live in a compensation culture - you love the car, does it actually make any difference when it was made?
+1 on Neils statement above.
I also echo what has been said by others in that the V5 generally shows the first registered date and that in many cases, specifically for imported cars, year of manufacture can vary from year of registration. I think the only way that you should feel aggrieved is if you asked the dealer if it was manufactured in 2009 or was a 2009 model and were lied to.
Lastly with my mod hat on please don't make unsubstantiated serious accusatory statements such as the dealer fraudulently falsifying the V5. You have not demonstrated any proof of either this being the case or more pertinently that the dealer has had anything to do with this hypothetical change.
In view of the above I also suggest/ask that you do not name the dealer.
Difficult, I appreciate, if you are genuinely worked up about this but just enjoy the car, take a free service (if offerred) put the roof down and drive.
