1. Sunroof Drain: The sunroof drain tubes could be clogged or disconnected, causing water to accumulate and leak into the cabin. Check the sunroof drains for any blockages and ensure that the tubes are properly connected and draining water away from the vehicle.
2. Rear Window Seal: The seal around the rear window may be damaged or worn, allowing water to seep in. Inspect the seal for cracks, tears, or gaps and replace it if necessary.
3. Taillight Seals: The seals around the taillights may also be worn or damaged, providing an entry point for water. Check these seals for any issues and replace them if needed.
4. Trunk Leaks: If the trunk of your BMW 318i has any leaks, water can seep into the cabin and accumulate in the back floor area. Check the trunk for any signs of water intrusion, such as wet carpeting or standing water. Seal any leaks or replace damaged components as needed.
5. Floor Pan Rust: In older vehicles, rust can develop in the floor pan, creating holes and allowing water to enter the cabin. Check the floor pan for any signs of rust and repair or replace the affected areas.
If you are unable to identify the source of the leak, it is recommended to take your vehicle to a qualified mechanic or automotive repair shop for proper inspection and repair.
