We've got the Long Range RWD - VIN 1576, so it's an early one... I've never felt like the ride was "jiggly" - it was too hard and stiff, and I'd describe the feeling of going over bumps more like "jostling" instead. Like the whole car would stiffly bounce, because the springs were too tight or stiff. Not sure if lowering the car would be right for you, if you're already hitting bump stops, though. I don't know if I've ever felt like the car hit the bump stops, actually. Earlier in this thread was a conversation about shipping blocks... maybe double-check that you don't still have those in place by accident? Which Model 3 springs for a more comfortable ride?