A160 - Shuddering at high speeds when going over small bumps/holes - Advice Please

[puds]

Could someone please advise me. I have a 2nd hand A160 (1999) which feels like it shudders/moves sideways when I am travelling at speed (50+mph) or going over small bumps/holes in the road. I bought it fairly recently and my C180 which I have had for a couple of years does not do this at all. I fully understand the difference in weight/ride etc but it is disconcerting when travelling at speed to feel like the rear of the car shudders sideways. Can anyone advise what the problem might be, is this common to old A160s before I go to a garage.
Thanks
Puds

 

[jibcl500]

Could be the rear trailing arm bushes need replacing, jack up a rear wheel and try pulling pushing the wheel towards you and away from you, if there is play there then they need changing, I saw some rear arms complete and new on ebay and they where cheap to buy.
Fitting them can be a fiddle but easy enough.

jib

 

[puds]

Thank you I will try that.
Puds