I have put high-grade bushings on ALL 4 frontsidepoints (not the back, just the front and not even the 2 holding the stabi) on my previous W221 and it handled way, way better in a stright line. Could even the steering loose and it went dead ahead. Before it sailed like a yacht and i had to correct the steerring way to much. And yes it was aligned by serval company with no noticeable difference. But after changing just those 4 bushings: hardley any play in the steeringwheel and the ride wasnt even harsher before they replaced them. If i didnt know they were fitted i would have guessed they just alaigned it tip-top. I dare to state the the handling was even smoother, like softer ánd directer. Less steerringwheelcorrections on straitroads where Semitrucks create ruting on the roads, it finally didnt try to get out of those ruttings and so pulling continous to left and right following you as a driver correcting that all the time. IOW qua comfort no noticeable decrease in hardness, only advantages in handling (wich i personally think isnt something Mercedes is good in since they put "comfort" as their USP. THose rubbers are worn too quick and without any cracks noticable they do get play and couse problems imo. I often have Fares to Belgium where the roads are the worst in Europe and even on that terrible Roman-era bigblock stone paved roads it was just as comfi you aught to expect. OK, i dont know wich grade/material poly is used on that Camber-rod but since the front-upgrade i didnt even concider that as a obstical. Replacing them is far easy than the OEM-rubbes ones. On the other hand, i have put those out of the box purple/black/yellow bushings from any wepshop on my privat car and yes, thát is throwing money in the drain and had play on the within a year and the ride was terribly hard and everthing started to rattle. Mine where from lets say other matarial ánd were by Lathe and pointspecific measured. Set me €600 back for the front only incl montage. Those cheap aout of the box sets costs €100. My W222 with 170k starts now acting up in a straight line and with sidewinds so ill keep you updated when its get that threatment also. Ill ask them wich brand and why they used and the make. And please its just my experince hé, im not trying to be cocky and maybe you are riht and sees that the material they used is rubbish so please reply with argument or example. Im no expert. I dont even know if the need lubrication after some time or not. I just want a S wich handles better than it did when i bought it. The ones ive bought had 200K and this W222 100K, "dealer" served but still allready slightly weaving even on quite good roads here in Holland.