Sounds like it's probably an engine mount failing then. A scan with VCDS should show it up.
D T's ?
My engine used to randomly judder at idle & fitting a new engine mounting stopped it. i've had DMF failure on a couple of VAG cars & both times the juddering at idle would stop on engaging the clutch.
Another way of checking the DMF is to hold the revs at 40ish mph in 3rd gear, & if the car surges your DMF is probably goosed.