215 cl500 versus 215 cl55amg abc suspension

[albertchampion]

for several years, and 27,000 miles, i have been driving a 2006 cl500[46k total]. i drive it with the abc "on" in the "c" setting all the time. and i drive fast.

i have found the drive to be supple, stable. and quiet when traversing harsh road irregularities.

and i expected the same with the 2006 cl55amg that i acquired two months ago. but i am now wondering if the abc suspension has been set up differently for this vehicle. again, with the abc engaged in the c setting, i find the rear suspension is very noisy over even minor road irregularities. and it feels like, sounds as if the right rear is rebounding multiple times, noisily, over even minor road surface irregularities.

initially, i thought that the issue was one of cold fluids, since i first noticed the issue during our recent below freezing weather. and the noise and the harshness tended to subside after about ten miles of driving.

i mentioned this to my dealer dervice gurus last week when the car was in to correct what the selling dealer, sfbenz, overlooked in their cpo exam. my gurus, whom i have known for 3 decades reported that everything checked out.

and indeed it did seem to run like my cl500 over the last few days.

but....today i took it out, it ran just like my cl500. then i parked it on level ground, on asphalt, during a warm afternoon[80F] for about 20 minutes while i did some business at the county courthouse. returning to the car, driving away, i found the rear suspension to be once again unnaturally loud when thumping over minor road irregularities. it sounded as if the right rear was double-thumping. over 20 miles, this noise and this harshness seemed to dissipate.

is there a suspension issue here that the dealer's service tech missed? or does the cl55amg have a suspension that is noisier, harsher than the cl500?

all ears.