Bought the X5 M54 6spMT back in Aug. 2014 with 110K. I am now at 125K.

- So far so good.
- Once you know the quirks of the M54, you will be fine.
- Trying to avoid newer BMW for now due to carbon build-up issues in the Intake Valves from direct injection system. Eventually, I have to deal with that issue if I decide to stay with BMW.
- Wash the car and under chassis whenever temp is above 5C to get rid of winter salt etc.

Just routine maintenance that I already did:
- Partial cooling overhaul.
- All fluids already renewed.
- CCV Mod.
- Window regulators clips replaced (not the whole regulator, just the clips). Now the driver's glass makes noise when going up. When going to work, I simply open the driver's door to swipe the parking pass (I avoid lowering the glass for fear it would not go back up). This Spring, when the weather gets warmer, I will install a brand-new BMW OEM Window regulator, which is around $110 or so.
- Can't complain b/c the original WR lasts some 12y/125K miles.

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1998 E39 528i 5sp MT
2006 E53 X5 3.0 6sp MT