Finally got the Techart/Eibach lowering springs on my car. Took about 5 hours and help from a friend to complete the job. R&R of the front really requires a second person to pry the lower control arm down so the strut can be removed. The rears can be done with 1 person.
Initial impressions - drop is noticeable, but not radical. Springs still are not settled yet and the front lip is at 4 3/4 inch clearance from the ground. Car has a nice stance now without looking like a 4x4. The ride - very surprising - I actually found the ride MORE compliant than before. I think the newer rates are better matched to the struts than the stock springs. Less po-go effect. Even in Sport the ride is good. No suspension noise whatsoever, no harshness. So far, very pleased.
As far as install needs:
you need a special ball joint separator:
OTC Tool Manufacturer for Cars and Trucks : Products
you need a special tool to hold the slotted washer of the front struts in order to remove the top nut. I happened to have this 944 tool which worked perfectly
9xauto's
the best tool I found to remove the top strut nut was a 13/16 spark plug socket
you also need a big pry bar, and a spring compressor
Front - remove front tie rod, lower ball joint, strut clamp and sway link from the hub carrier
Front - remove wheel caliper and lines from hub carrier, then pry down the lower control arm and rotate the strut out of the wheel well rearwards
Front and rear - use spring compressor to unload spring/strut top nut, then undo nut and swap out to new spring
Rear - undo sway link and rear trailing arm (optional) from rear hub carrier
Rear - remove Bose subwoofers, mounting brackets, and insulation to expose spring mounts and then undo spring mounts (must disconnet PASM wire first front and rear)
Rear spring installed - new spring appears to be progressive vs stock spring
Front spring installed - top and bottom coils are covered with additional damper material to prevent coil bind and noise
Before:
After:
