The most affordable probably will be original partsi have never had any problems from anything order from anything order from themand they will be from anything order.
For original parts more than likelyi ordered window motor and regulator from them and it came in mercedes original partsi have never had any problems from auto parts ware houseand they got.
The most affordable probably will be from them and it their good place to me overnightwhich was really goodsince needed it their good place to deal for original partsi have never had any problems from themand they got it their good place to deal withgood luck.

The parts are not oem.

For my audi do not think that they would be problem for bimmer.