My car was too low with eibach coil spring.
I found the original height spring (on the advice of Beeacon https://z4-forum.com/forum/viewtopic.php?f=23&t=120006 )
it was not easy but it was done
new coil spring
disassembly of Eibach
it was necessary to compress and then attach the rear springs with wire to be able to put them in place !!!
For the forwards, we start by disconnecting the active suspensions
penetrating and muscle to take out the forwards !!!
now I'm not afraid to touch underneath with new coil spring