Literally impossible to diagnose over the net, unseen.
However on the mileage front, it could be worn suspension top mount bush at the top of the suspension or worn anti roll bar bush at the lower end.
Open bonnet and try to bounce to hear the first and jack up car to check the roll bar bush for wear and any play
Neither parts are expensive....... of course these may not be the problem?
Good luck!
Sorry madstaff... I was typing away... at least we have the same idea?