Man, you will get screwed if you buy 325is seats. The are just not enough for lateral support. I do not know how many times I have hit my a pilar with my head in my car racing at the track. First time I hit it was during 4 wheel drift at a mall structure right where I live and since then I always have one helmet with me in the car.
They look nice, but if you are looking for lateral support they will not bring you far unless you got a 4-5 point harness mounted on them.
The other option thoug is to change the angle and engagement point of your e-brake so that when you hit corners you hold on to it with your right hand REALLY tight (hmmmmmmmmmmmmmm....sounds almost like somebody's done it