I have read this thread with interest as, until a couple of years ago, I though the same, BMW, Audi drivers etc......
However after owning a couple of fairly dull cars I did some sums and, to cut a long story short, I bought a 2007 BMW 525d.
What I see now is the other side; drivers who don't let you out, who close the gap, cut you up and generally think it's hilarious to tailgate. The chief culprits are lareg 4x4s (Range Rover/Cayenne/Q7s), Vectras and white vans.
Well, mostly it doesn't particularly bother me (apart from the tailgating which I detest) I know I've got one of the best driving saloons around; 7.4 secs to 60mph, 50mpg (not at the same time though) and band G emissions - what's not to like?
I'll live with the "stigma"