I heard that the new M3, the next iteration, is under consideration for the installation of a V8 from the factory.
This is (allegedly) in response to the IS430, the Lexus, which is receiving a 4.3L V8 in coming years (2005, I believe).
I remember reading this in Car and Driver, AutoWeek or ROad and Track in one of those spy photos with captions, but I have not seen or anything that led me to believe that this was a done deal.
As for listening to dealer's bs, let me just say that in 22 years of buying cars, I could count on one hand (with four fingers left) the number of dealers who actually knew anything about the cars they sold. When I bought my M3, they had to read the manual to learn how to start the car and move it forward from the back lot to deliver (no one knew how to drive an SMG car...or start it, for that matter).
However, if they DO install it, one has to wonder if it'll be able to be retrofitted to the existing M's. If not, is it worth trading ours in?
My wife is looking at the 6 series...I want her to get the M6, but it'll be $80K and I can think of several other cars I'd rather have (TechArt 996 non turbo) or even an SL500...and having just finished modifying my M3, I don't see me selling it anytime soon....