If you didn't have a pre purchase inspection done, I would have that done to see what a well recommended independent shop that specializes in BMWs has for input looking over your particular vehicle in person. If you have history of ownership and maintenance that will help tons.

You will get suggestions of a bunch of preventative maintenance repairs to consider that can cause buyer remorse if you let them. Only 75,000 miles and obviously well taken care of is a good indication it is in good shape.

There are two entrenched camps about changing transmission fluid. I am on the yes side. I drive hard and have done many engine mods. I change fluid and filter every 40,000 miles. I have 118,000 miles on the original transmission with no problems. The only potential other reason I have had no problem is the Dinan trans software installed at around 1,500 miles. I use the ZF fluid. My basis is 20 year veteran of working on BMW transmissions that advised there is no such thing as lifetime fluid and recommended the interval I use. That doesn't mean I am the yes folks are right. Suggest you ask someone of the caliber I did and see which side he falls.

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas