Originally Posted by derek0812
Couldn't agree more that the ride height on the xdrive is a joke. I bought mine new and thought I could eventually get over the look of it, but there was just no chance. I just ordered new KW V1 coilovers last week and can't wait to drop it down and see how much better it will look.
Any suspension changes you make will affect the warranty. In other words, if BMW determines that something on your car failed because of the suspension mods that you have done--it won't be covered.
The good news, is that there is very little chance that the suspension modification you make will cause you something suspension related to fail and not be covered by BMW. For instance, the KW V1 coilovers come with a lifetime warranty--so if anything happens then you would be going to them for a replacement rather than to BMW. Not sure about the warranty relating to Bilstein/Eibachs though. The dealership will know if something has been changed. Many people change suspension on their BMW--you shouldn't worry about the BMW warranty regarding suspension too much.
Also, you won't want to put ZSP springs from an "i" on your "xi" with stock shocks. There have been numerous threads about bouncing and it wearing out the stock shocks very quickly. You are better off replacing it with coilovers or sport shock/spring combo.
The only thing I can think of that would effect the suspension is maybe the sway bar end links needing to be replaced because of the drop in the car and that would not be covered by a warranty.