Headlight vibration problem

Okay my friend has a '00 Pontiac Firebird and recently her car has begun to have her headlights shudder terribly. Everytime the lights go down they make this loud noise, and vibrate terribly and go down slowly. Anyone have any ideas? Has anyone ever seen anything like this. Thanks.

No problems with mine.
Take it to the dealership, tell em to fix it under warrantee.

There is a plastic gear in the motor housing that is stripped. The headlight only uses half the gear, so there is a 'fix'. Here is the link.

http://www.bfranker.badz28.com/headlightfix/index.htm