Welcome
I'm still dealing with this issue in our '03 PTGT.
I replaced the plugs & wires like Don suggested which made it a little bit better.
I then added some additional grounding, which helped marginally more.
There are other factors that I still need to assess since we bought the car used (balance shafts still intact & indexed?, motor mounts good and unmodified?, etc.), but since it's been bloody cold around here lately I'm making slow progress at determining how to improve it more.
Brian