it's possible some weights came off.

 

^^that could be the problem. have seen that a few times.

 

did you notice the problems before the new tires and alignment? Or is this something you noticed after? Do you get the vibration while cruising, accelerating, braking?

most dealers and shops would have to charge to diagnose the problem. Then if it's a warranty item, it would be covered. Otherwise you would have to pay for the repair and diagnosis.

 

In fact, I would take the car back to where you had the tires and alignment done, and ask them to road test the car and double check their work. They should be able to warranty their work. Or at least give you an idea of where the vibration is coming from.