My left rear shock was leaking and I noticed the back would bounce more than it used to. I have the magnetic ride performance suspension. I wasn't interested in converting to non performance. I expected a very high price for them as they used to list for over $800 a piece. I was able to get both shocks for $726 shipped. The install took about an hour and was easy to do.

 

Omac, Just read your post and I had same problem (left rear) on an 03' DTS. Unfortunately I went cheaper route. Installed a pair of Monroe 855 air shocks for less than 100 but now I cant find anyone that plugged in resisters to elect. harness to "fool" ride control system. Speed is limited to 90mph and ride is a bit stiffer & car sit a little higher at rest. I'm original owner & it has been garage kept with 85,000 mi. and makes a perfect "grocery- getter" (wife loves it). I didn't want to spend the $550 each on magnetic shocks as car is quite old.
Did you come across any of this info in your research? Where did you purchase yours?