On the Mini Cooper, lift a wiper arm and identify its end before buying: the attachment type decides fitment far more than the length, and a blade of the right length with the wrong end will not clip on. Expect the driver blade to be longer than the passenger blade, typically by 2 to 4 inches.
Three products we would look at first in this category. Fit for your Mini still comes first: check the compatibility list on the listing against your exact model and year, and read the model guide above.
BoschAerotwin A864S Flat Blade Set (650/450 mm)
Front pair of flat blades; match the two lengths to your car before ordering.