actually it sounds kind of funny but once i hit a crazy bump on northern blvd queens with my m3, and as soon as i hit the bump i shifted hard into second and the trany broke it got stuck in second.....

I would say just to be careful with the speed bumps. Clutch engaged or not. Just go over them slowly.

just drive the car holy crap, use common sense...
many experienced drivers say dont use the clutch unless you have to, and that the car should always be in a gear while moving.
but common just drive your car it isnt going to fall apart from going over speed bumps(unless like stated above your hitting em at speed).