Some Lexus IS350 owners report experiencing water leaking into the cabin, often due to a blocked evaporator drain caused by debris. This blockage can lead to water accumulation, necessitating prompt clearing of the drain plug to prevent further issues. A common symptom of this problem is a sloshing sound within the vehicle. To resolve the issue, some owners have successfully cleared the drain tube by blowing air into it or using a coat hanger wire to remove obstructions. Additionally, it is crucial to address any cracks in the evaporator drain pan quickly, as small cracks may require a waterproof sealant as a temporary fix, while professional assessment is advised for potential replacement. Regular maintenance checks are vital to avoid leaks from a clogged drain or a rusted condensation pan, ensuring that the evaporator coil functions effectively and preventing water from entering the cabin.