Only problem I have had with the car that are major are as follows:
Air Conditioning stop working 4 years ago. To costly to fix.
Water enters the car in the winter and the carpets get all wet, need a fix for that.
Paint is peeling, likely cause is that the car was parked in a factory lot for over 8 years.
I like the car and would keep it if I could get the wet carpet issue resolved.
The car has had general repairs, at minimum cost thanks to a hard working mechanic. He will go to a scrap yard to get used parts that are like new.
The leaking on your floorboards.. Don't ignore that Its your heater core!!! May sound bad.. Its about 300 to fix.. but.. It will save You money in the long run. Because I let mine go and go and go. Then finally.. When I got my heater core fixed. I got a crack in my radiator. And That was another costly fix. What happens when the heater core goes.. Is all the water from your radiator. (Coolant) ends up on your floor board. Which means guess what? You have no coolant. So keep that In mind. Otherwise you are lucky that you only have had a couple of problems with your grand am.