Leaking or Flooding?

[khiarrr]

I have a 2003 H2, I've had it for a couple months, but my dad drove it for a couple years before that...

I recently noticed that the carpet was wet, it was pretty bad, the insulation was soaked, and the carpet was wet all the way to the second row of seats, it messed up my DVD system...

I took it to the dealer the first time, they said it was from the truck lights on the top, and they told me they fixed it...
When they gave it back to me and it rained again, the same problem occured.
After the second time, the problem still happened when I wash my car...
After their third try at it, it still leaks...

Any ideas why it's happening, or what I can do?

Any chance its a lemon?