Morning Mark
The BMW straight six is one of the worlds great engines in either flavour. My brother inlaw has a 530d touring he commutes into Holland every week it is approaching 300k his previous 525d touring went beyond before he changed it.
Both cars were/are BMW history to 100k then his local independent Garage plus we have the odd fiddle if something stumps them.
As Trevor says at 140k is no mileage for these engines if they die it;s normally abuse not use. If I were you no matter what the book says I would give it a full service (engine, gearbox and diff) plus check the suspension shocks springs and bushes. Life for the bushes seems to be around 80k in my experience.
Good Luck
Dave
I suppose the philosophy here is that it has already done 140k miles then it probably won't go wrong now.
Also, being from 2004, an era which produced good quality cars its unlikely that there is too much to worry about.
Always worth staying on top of any maintenance tasks and should go on forever.