I'm a happy new '09 X5 35d owner (5 weeks and 1,230 mls ago)! I'm also a long-time VW Turbo-Diesel owner with 100s of thousands of miles on those engines.

Properly maintained, VW's turbo-diesels will handily go 300,000+ miles without breakage of any kind, including the turbo. It's a matter of keeping the engine clean, with good synthetic oil, belts replaced, etc. I have 140k on one now and it drives like the day I bought it brand new. I've only ever replaced the wearable items/fluids.

I REALLY hope my X5 will mimic the engine longevity of the VW engines.

Some folks have reported VW diesel reliability issues, and more times than not, those complaints can be traced to some (or several) wearable items not being properly replaced or parts not being properly cleaned (injection systems gumming up, etc.).

Hope this perspective helps.