just got mine back from been in at the local dealers for the same problem.
they was unable to find a fault, they said it shudders around 1300 rpm, they have contacted vw about it and will be getting back to me next week with what there reply is.
i first noticed it a few weeks ago when the car is stationary.
Theirs no movement in the rev counter when it does it.
is this happening on ko3 and ko4 engine's?