Thanks to my buddy Ted at Monkey Wrenches in Brentwood I was able to get coilovers installed on my 98 318ti. I chose the Bilsteins because I started autocrossing the car and also plan to start doing track days in it; the added adjustability is going to be helpful.
the job was not really that hard except for the rear spring removal - needed to disconnect the axles from the differential as well as the sway bar links. We were able to do the whole job without removing the rotors or calipers.
Looking forward to my first track day at Laguna Seca in May!
The car before 
The kit: 
Old rear spring compared to the new one Getting that old spring out was the hardest part of the job! Note in the picture that the axle is disconnected to get that rear end to sag down enough. We still need a crow bar to get the spring out.
Rear shock & spring installed (easy) 
Front strut installed I expected this to be the most difficult, but it was actually fairly easy - 3 nuts on the top, 3 bolts on the bottom. Compress the old spring - take the factory hat off the old strut and put it on the new Bilstein Coilover.
After 
Bilstein PSS9 coilovers installed 
Threaded Mode