On my recent auction purchased 406,I have just done 1500 miles on a round trip into France,and unfortunately,the rear horizontal link bars had to be replaced while I was there,as the old ones had expired.The idea was to get back to Britain and have the bars replaced here.Anyhow.....
The car still has a slight vibration to it,insofar as it lasts about 3 seconds,and repeats every,say,5 seconds at speed in excess of 60mph.
Before I went,the tyres were replaced,and the wheels balanced,so I think that's covered,and I do have another theory,but I want to throw it open to you guys for input.
So........