According to Realoem - seat frame bases are the same part between F2x, F3x and F8x
52107243525:-
http://www.realoem.com/bmw/enUS/part...&q=52107243525
52107243526
http://www.realoem.com/bmw/enUS/part...&q=52107243526
This is a good start but by no means definitive - bolsters etc dimensions would need to be checked to confirm space is adequate in F2x.