High speed vibration

[Saff]

Hi People its been a while since I last posted on here, due in the main to Mrs Saff having been unwell. Thankfully things have improved now.

Back to the infernal vibration. It could be that I've just become used to it and subliminally accepted it as normal but I don't think so. What has happened is that the vibration appears to be road surface-affected,that is, going north on the M6 from junction 27 to junction 36, it is almost imperceptible. The return journey is vibration as usual. It doesn't seem to be coarse or smooth surface but the even-ness of the surface. This would seem to eliminate the propshaft as the culprit. I know issues don't just go away on their own but it really has improved. Unless I'm going barmey which is always a possibility. Any thoughts anyone?