here's an update on my 170,000 mile SRT6 with the "Shudder" problem.........
.....the shuddering seems to happen mainly on light or gradual acceleration....whether at low speeds or highway speeds---in any gear. When I accelerate hard, it feels smooth and normal--almost no vibration.
Sometimes I'm convinced that it is a driveline problem, other times it feels like an engine mis-fire.........think I'm going to contact these Needswings guys.........