Water leak in the passenger side.
The leak is not caused to off-road use.
I purchased my Jeep Liberty 2002 6 months ago at a CarMax Dealer. It currently has only 18k miles. I myself is experiencing a major leak problem. I have never went off-road with it but noted a leak on the passenger side(front and back). I have been twice to the dealer. The first time, they replace a clogged pipe used to remove the condensation. The second time, they had to remove the whole dash and replace the conductors from the air-conditioning unit. To this day, there is still a leak and does not know if it is coming from the rain or the air conditioning. I am scheduled to go back next week. They will look underneath the carpet and simulate a rain while running the air con. Plus they will replace the carpet since it is starting to create moles and smelling.
Check out www.kjjeep.com, in the forum the leaking issue is mentioned, it could be the drain from the sunroof (if you have one) or it could be a missed welding- point just above the windscreen.
I had the same problem this summer on vacation. Our Jeep was sopping wet on the passenger side front and rear our entire trip. My husband checked into it when we got home and found a garden hose size drain hole under the hood and on the lower passenger wall of the car. Water was drizzling out of it with the cars air on. He proceeded to put a section of garden hose over the drain and ran it under the vehicle tywrapping where necessary. This was our cure!! We had Cryslar look at it and they said it is a great fix and that they would have done similar so we have left it in place. Wish that was our only problem we have had, but sadly it is not and I am ready to sell!