there are a couple of places where the car can leak - you can start with
these checks:

1. it is common for the rear hatch glass to separate from the frame - this
starts along the top near the hinges and spreads across the top of the
frame - this lets water in but it usually drips onto the carpet along the
side in the very back.  The solution to this is to remove the hatch, take it
apart, cut the glass free from the aluminum frame, clean everything and glue
it all back together - there is a FAQ on this - but please ask me before you
do this job and I can offer some important advise

2. the metal under the battery can rust through, this will put water on the
floor in front below the battery - I suppose this is a good place to look.

3. I have had water come up through the floor when one or more of the rubber
plugs is not in place to seal some openings - unless you are in deep water,
I don't think this is very likely

4. there may be rust around the windshield - I have had this happen on other
(much older) cars, and the rust is hidden by the trim.

Can you get a hint as to where it is leaking?  usually water will leave a
bit of a trail that you can see if you lie on your back with your head in
the wet spot and look up (you will want a good light when you do this)