1. Window seals: Check the rubber seals around the window for any cracks or damage. If the seals are damaged, they will need to be replaced.
2. Door weatherstripping: The weatherstripping around the door may also be damaged or worn out, allowing water to seep in. Replace the weatherstripping if necessary.
3. Clogged drain holes: There are drain holes in the door and window frame that allow water to drain out of the car. Make sure these holes are clear of debris so that water can drain properly.
4. Loose bolts or screws: The window may be loose due to loose bolts or screws. Tighten any loose bolts or screws that you find.
5. Misaligned window: If the window is not properly aligned, it may not seal properly and allow water to leak in. Adjust the window alignment if necessary.
If you are unable to find and fix the leak yourself, you may need to take your car to a mechanic for further diagnosis and repair.