2 problems need help

my car is a 1991 cavalier rs 3.1L V6

1st problem my car has got a water leak but only the floor behind the driver seat gets soaked and i cant find the leak.

2nd problem i had a an oil filter that couldnt come off and now only the top of the filter is left and screwed in and i tried everything to take it off but it wouldnt budge (p.s the oil filter is destroyed on the top part is left.)
thanks

water leak- check under car, there are rubber plugs in the floor. when they get old they can fall out. on oil filter, turn to the left , counter clock wize. With the filter destroyed, you will need to chissel it off any way you can...they are only supposed to be put on hand tight...some get carried away when putting them on. hope this helps. Later, Mark

Almost forgot... if you can see where the oil filter screws in, then you can get a large allen wrench in the center, then you will remove the filter and the filter mount together, then just a matter of getting the thread insert out of the filter. Later, Mark.

Hehe... i am experimenting with oil filters. best design so far has been the fram sure grip.. currently i have the K&N gold on there... pain in the ass, but it has a spot to use a wrench if need be to take it off... THe also make a wrench that grips around the outside if it gets too tight..... Oh and P.S... so far the K&N is making my car act weird... so no one buy them... going to install one on a buddys car and see if it happens to his aswell...