I did not need to modify my linkage at all when I swapped in a Z3 rack into my airbag car. You need to do 3 things:
1. Spacers (I don't recall if you put them under or on top of the rack)
2. Make the hole in the firewall that the column passes through a bit larger. You can Dremel out the lower-left (as seen from inside the car) part of the hole to expand it ~20mm for clearance.
3. Bend the power steering hard lines a little. You need to be very careful here because the metal hard lines are very stuff and you have to push hard on them, while also not kinking or collapsing them.