I don't think yours will be caused by the vss, it's more likely to be an earth I think. Just do as I did and try chasing the earths around the engine bay, I got lucky finding that one as I have no idea where an of them are. Or if it's not an earth then I don't know what yours is, but I'm sure someone will know
Or could be engine mount? If you don't have any other electrical issues then I'd put a juddering down to engine/gearbox mount, again someone will correct me if I'm wrong
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supercharged China gti6 - Thu 16th Sep 1999 - sold2010 megane rs250