Considering just how important the water pump/ thermostat are to the engine and how prone to failure the OE parts are why look for inferior makes? A good friend has a saying: "Everybody always has enough money to do it right the second time."
I admit to being a price shopper but have learned the lesson that buying the cheap part, fitting it and having to redo the whole thing again when it fails is always more expensive than just buying the more expensive part in the first place.
FCP offer a lifetime warranty and you know if you keep the car it will, most likely, fail again. They pay for the replacement part. Save yourself the cost of cheap part then more expensive part and do it right the first time.
GL.

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2021 X5 xDrive40i
2015 X5 xDrive35i MSport
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