I learned the following from the FAQ http://home.earthlink.net/~mrbadss/c...tml#suspension site:

FE3/FE4 Suspension Part Numbers
Thought you guys might like to know the front/rear shock part numbers for the FE3 suspension:
Front (w/o spring): 89047751
Front (w/ spring): 25753477 (Left) & 25753478 (Right)
Rear (Nivomat self leveling): 25754648
From what I can determine, the springs are the same between the Soft-Ride and the Sport.
Also, The front sway bars are the same. The rear sway bars are different. The part number is 25684658 for the FE3 rear bar (don't know if that includes all hardware?)

Now, here's the FE4 suspension stuff (CTS-V) [not showing available yet]
Front shocks (w/ springs): 89047658
Rear shocks (Nivomat self leveling): 25752922
Front sway (w/o hardware): 25752682
Rear sway (w/o hardwarz???): 25762623

I can add the following:
My CTS-V rear springs have are # 25752977