I put the 18 way adjustable E38 seats in my 2003 E39 Touring. I have seen them referred to here as the "sport/comfy" seats. Anyway, they are the ones with the upper back adjustment.
I love them as a driver. My wife just goes "ahhhhh" every time she gets in the car after not being in it for a while. However, they were meant for a vehicle with a longer distance between the front and rear seats. They don't have a concave knee accommodation for back seat passengers. I'm 6'2" and can sit behind my seat adjusted for me to drive. But, getting in and out isn't so nice. Once in the rear seat things are ok. My son is off at college so it really is just the two of us and this isn't an issue. I wanted to make sure though that people reading this thread are aware of the seat back design difference.