This is a known Genesis issue, and there is a technical service bulletin issued to address it. I was unaware of the problem, knowing only that after a heavy rain, my front floor would be soaking wet and the headliner above would be damp. Owners on other sites have posted complaints, which alerted me to the possibility that is was a plugged drain hose in the sunroof. I have received no communication from Genesis of the potential for this problem, but the TSB states the repair is covered under warranty. Parts need to be ordered, and the dealer may need to be guided to a solution. If ignored, this could be a serious problem, with other owners noting that it has resulted in expensive damage to electronics when the leak entered the dashboard and/or the center console. This is the first time I have experienced a leaking sunroof, though I have owned cars equipped with sunroofs for decades.

Noticed that water was pooling behind driver's seat on the floor and saw some running down side of rear seat. Thought it was a door seal leak. I also saw water droplets coming out of vent in cargo area. Thought water was somehow getting into heating vent system.

It turns out neither were true. The dealer identified that the sunroof leaks on rear corner. Water drops directly down onto side of rear seat and pools on floor. It also runs behind headliner and wall panels to rear cargo area and comes out of the vent on the wall. That vent, they tell me, is only decorative and not linked to heating ventilation system.

So, entire sunroof must be replaced. Big job. But, it's covered by warranty.