Here is my story of buying an owning an 11 year old 100'000+ mini Cooper (R56 non S).

Here is the advice I would give!

1: Has the clutch been done?
2: Buy an OBD scanner and read any codes.
3: Has the tensioner been sorted and the timing chain changed?
4: Look at the oil and coolant carefully.
5: look out for white smoke and rough idling.
6: keep some cash aside as they need a lot of care because I doubt you will find one with all this work done.

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