The Bilstein sports are pretty harsh. I like the heavy duty and they work great with lowering springs. I have suspension technique springs myself. They have the least drop and are cheap. The Bav auto are probably the same. I recomend either over the too mushy stock springs. Ditto on the boge shocks. Too soft, they seem better on other BMW's. Eibach and H&R springs are great too but overkill on a 320i in my opinion.