Wow and I thought I put a lot of miles on my car. Mine was delivered in October 2009 and I'm at 38500 miles now.
She's been in the shop a couple of times, twice for software glitches, and many times for the low DEF warning - which turned out was caused by the mechanics not filling the tank up properly.
Still love her to death. The best mpg I've seen out of a full tank is 37, and that was about with about 70% highway and 30% city. I haven't taken a long enough road trip to see what kind of mileage I would get out of a full tank of highway driving but I suspect it would be well into the 40's.
Then there's the power, which goes without saying. I tend not to street race, but in my two years of ownership I've had a few friendly run ins where I've been able to surprise a couple of 350z owners, keep dead even with a 550i, a 335i, and a Boxster S. My favorite was when I pulled alongside a couple of guys in a C5 corvette who owned a tow truck company and couldn't believe my car was a diesel. They couldn't believe it when I told them I was getting 34 mpg in mixed driving, even less so when I showed them my taillights up to 80 mph and they couldn't quite pull past.
Sorry, I didn't mean for this to turn into a mini review but there you have it. No other car comes close to the combination of performance and efficiency of the D and that's why I love it. But we all already knew that didn't we?