your car uses air shocks on the rear -
OK - OIL FILLED SHOCKS THAT HAVE AN AIR BLADDER
CONNECTED TO A COMPRESSOR
TO MAINTAIN PROPER RIDE HEIGHT -
like I said - air shocks -
any replacement shock you choose will be an air shock -
except if you go with a coil-over shock
because the compressor is shot - but that's another story -
you only have a couple choices -
stay with the "ACTIVE" suspension and spend the big bucks -
but you can still save some money compared to OE -
Monroe - LEFT - #40029 - $372.35 with free shipping from -
http://www.autopartsway.com/Part.cfm?40029/MON
and - RIGHT - #40030 - $372.43 with free shipping from -
http://www.autopartsway.com/Part.cfm?40030/MON
these are direct replacement units for your "ACTIVE" suspension -
at a substantial savings compared to OE -
-------------------------
the other - MUCH CHEAPER - solution -
is to go with "PASSIVE" rear shocks -
just like the base model Deville and DHS use -
Monroe #MA822 is an EXCELLENT replacement -
it uses the factory air lines - simple plug-n-play -
and you won't believe the price -
$50.98 - FOR THE PAIR - YES - BOTH REAR SHOCKS - with free shipping -
http://www.autopartstomorrow.com/part_numbers/269835-rear-max-air
so - "what's the catch" you ask -
the "PASSIVE" shocks use a fixed valve that doesn't change -
the "ACTIVE" rear shocks use an electronically adjusted valve
that can change how the shock works -
it can go from a soft ride - to a very stiff ride -
in the fraction of a second -
the computer receives all sorts of input from a gazallion sensors -
speed - direction - braking - accelerating - etc -
analyzes that input - and changes the shocks -
IF you really drive the car in a "spirited" manor -
you might feel the difference between
an "ACTIVE" and a "PASSIVE" suspension -
SOME of the members will tell you
if you don't replace with the "active" shocks -
you no longer have a DTS - yadda - yadda - yadda -
I say - if you don't "drive on the edge" -
you'll never know the difference -