If you're set on this particular example then there are a couple of thing you could do that might help. Since it was purchased from a BMW dealer local to you, perhaps you can get service history from them. Then, have the seller take it to a BMW dealer or qualified independent to do a once over for you at your expense. The couple hundred it would cost you could pay for peace of mind or save you from a nightmare.

I have another idea for you I will PM.

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