I only took seroquel for a short while, about a month. I have had similar side effects too. My legs would move involuntarily, but only when I was laying down, or in relaxed state. My hands would tremble, but not too bad. I have read on the website and Seroquel can do that to you, when it 1st happend it scared me. But I stopped taking for other reasons. I would talk to your Dr. if it is really bothersome.
"What is life? An illusion, a shadow, a story,
And the greatest good is little enough:
for all life is a dream, and dreams themselves are only dreams."
~ Pedro Calderon de la Barca, Life is a Dream