I find water on the floorboard carpet of the cargo area when it rains. Also, the passenger's side heated seat light is on, but the heater is not working.
Have a mechanic check the exterior of the vehicle for possible damage to weather seals. The interior panels can be removed and a light stream of water can be poured along the outside to find where the water may be sneaking in. This is generally the type of concern better handled by a body shop or collision center as the vehicle body may likely need repairs.