There are four drain hoses, one in each corner of the sunroof. The front ones run forward from each forward corner to the A pillar on each side, down the A pillar, behind the dash and exit at a nipple in the rear of the front wheel well, under the plastic fender liner. The rear hoses run rearward from each rear corner to the C pillar on each side, down the C pillar into the trunk, and exit at a nipple in the front of the rear wheel well, under the plastic fender liner.
Slide the sunroof rearward and pour some water into each front corner (you can see the drain holes). If the water comes out at the rear of the front fender wells the drain tubes are okay. Close the sunroof, then open it in the vent position. Pour water into each rear corner (you can't see the drain holes) and observe where it comes out. If it comes out the front of the rear wheel wells the drain tubes are okay.
If you have water dripping down from the headliner, one of the drain tubes has become separated from the connector on the corner of the sunroof assembly. This happens very easily since the hoses are not clamped in position. To fix this, you have to drop the headliner to access the connectors. Remove both sunvisors, the left grab handle, the left A pillar, and the left B pillar. This should allow you to drop the headliner enough to see the connections.
When you put the connectors back on, add a nylon tie strap or a small hose clamp so the tube doesn't pull off again.
Jack each corner up, remove the wheel, remove the fender liner to expose the drain nipples. Gently use a staightened coat hanger to clear out the mud and debris from the nipples until water flows freely.
If, instead from dripping from the top, the water is in the rear footwells (where the rear passenger'* feet go) one of the front drain hoses has come loose behind the dash. Let me know if this is the case and I will direct you to a post outlining how to fix that.
Based on your description (water dripping on passenger seat) I would bet one of the tubes has come off the connector at the sunroof assembly.