My Volvo s40 only leaks water when it rains so I know it’s not the A/C. The tray were the windshield wipers sit. When it’s full of pine needles the water doesn’t come through as much. Whenever there’s nothing and the car is clean it’s a puddle in the floorboard.

 

Do you have a sunroof?
What year car?

 

yes I do have a sunroof but I think it’s the drain up by the hood that might be clogged.

 

The was a so called "Silent Recall" on the sun roof drain port clogging. I just had to get the CEM replaced on my daughter's car due to water damage.

 

Easy enough to check the sunroof drain(s). Just open the sunroof, and pour a quart of water in on the outside (drainage side) of the channel, on both sides. If it runs right out, you know the drains are working. If it doesn't (or if your carpet gets wetter) you have your answer, too...

 

Sunroof drain tubes clogged or disconnected. These run along each side of the windscreen behind the trim. There is a youtube video that shows how to fix it. Not sure if that is your issue but it is common.