2011 Prius. Leaking fluid on floor of front passenger seat.

it's usually a clogged ac drain tube:

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First you need to determine is it water or is it coolant antifreeze We need to find out any free smells kind of crappy when it's got air on it and sitting on carpet as does regular AC not draining so just pick your poison I personally would roll the car up on ramps and find the AC drain tube in the middle of the front end hanging off the firewall or wherever it is it's just a little rubber tube and it's where the water drains out of the AC box from inside the car You run a coat hanger carefully and see if you pull out any dung and if so you do it again there are kits where you can get a tube inside the car to run into that evaporator box then you can spray this chemical in there that'll kill mold and all this other nonsense make it smell nicer whatever and then you can run some water through that tube and see if it'll run out as fast as you're running it in All this is being done with you know like 8 mm tubing or something so you're letting water go into the evaporator core and you're watching it with a camera or whatever coming out of the drain tube at about the same speed you're feeding it in so it's not building up in the evaporator box it's coming right out of that drain hole maybe some gunk is being pushed out as you're doing this now you can withdraw the tubing you're feeding the water with after this is draining correctly and see if that resolves your water getting in the car issue If it smells like coolant I guess it could be a bad heater core or something like that.