ive been pondering this for a while now. Im thinking of putting m3 seats in my r50 cooper, im 6ft 1 so id like the extra lumbar support. i know the rails wont match up perfectly but is there some sort of adapter bracket i can make? any input is appreciated

 

The only way to tell is to make some measurements. I've adapted seats in a number of cars, as long as they physically fit, you can buy universal rails that can be drilled for your needs. You just match them up with the existing mount holes in the car and seat.