Originally Posted by Thumperx
I think your model is considered as a standard model, so it may came with standard height springs (as you found out). According to your OP, the new shock has helped the springs to bring the car to its proper road height. I think regardless of make any replacement shocks may do the same thing.
Plus, when you changed to the 17 inch wheels from the 16 inch wheels, you have increased the height by that 1 inch or so. As you have already researched, you can use lowering springs or spring perch drop units (usually used a the front) to get it back to the height you desire. This is your best bet.
Changing the bump stop does absolutely nothing to lower the car except to increase wheel travel, which can be a good thing in certain circumstance.
Good luck and keep us informed.
Thanks very much , but my car height is abnormal compared to any other e90s in egypt with 17 rims , we dont have sport suspension here even the 330i which costs around 80k $ doesnt come with zsp , so iam sure i have something wrong