Your car looks great with our Hyper Black ARC-8's! The ride height does look low but as long as you are not rubbing anywhere than it is safe. The front suspension works the best with at most a 1" drop in ride height. Otherwise much lower and the geometry of the suspension is beyond what BMW designed as a working optimal range. Camber curves and geometries of the suspension start to become unfavorable. Raising the car up will always improve the ride but if you do not have any problems now than I would keep it as is
