I'm currently rebuilding my front suspension (rear CA bushings, outer ball joints, strut mounts, springs, wheel bearings, etc). Car already has Bilstein HDs. I ordered the H&R 50409 iX spring kit on eBay and the fronts are labelled 50404.55. I'm getting conflicting information that the 50404 springs are for the M3/318. Although ECS has the 50404.55 springs pictured in their 50409 iX kit. Any help? I was initially concerned because the front springs were much shorter but didn't feel much stiffer than the stock spring, so I looked a little deeper. I know the iX springs aren't supposed to lower the car as much as a standard e30.