2005 Honda Accord

You should start to look on door sealing strip. Check sealing strips still there attached properly or ripped pr damaged. If it looks fine, check door(s) close properly with out gap. Sometimes people forget key inside car and stretch door frame to stick inside and try unlock. that cause big gap on door frame. It cause water leak. If it smells like coolant for sure it is heating core failure. Turn heater on and wait 5 to 10 mins when smell under glove box. Hopefully it is not heating core. I hope that will help for your question...

Do you have a sunroof? If so check drains holes by pouring water down them. They are in the sunroof area towards the front. See if the water is getting in floorboard when you pour the water in or if it is coming out under the car near front fender. If no water coming out under car its probably going to floor board. I had same problem and the hose that runs from sunroof to exterior of car had come unattached between the interior and exterior of the car. Very hard to get to but can be fixed on your own with extra long pliers and some glue.

Do you have a sunroof? If so check drains holes by pouring water down them. They are in the sunroof area towards the front. See if the water is getting in floorboard when you pour the water in or if it is coming out under the car near front fender. If no water coming out under car its probably going to floor board. I had same problem and the hose that runs from sunroof to exterior of car had come unattached between the interior and exterior of the car. Very hard to get to but can be fixed on your own with extra long pliers and some glue.