Yup. That would be my first guess depending on where it was wet and what way it radiated out.

First thing I'd check is if your drains in the the sun roof tray are clogged. If so, that can explain your problem. They come out and the bottom inner sides of the rear quarter panels.

Is it just part of the headliner that's wet or the whole thing?

If it's one area then you have a better chance of finding the source however there's also a phenomenon called capillary action. Think of what happens when you dip a napkin down into water. Water will travel up the napkin.

If the entire thing is wet, then certain areas that I'd check would be your windshield, holes in your roof (the stock roof rack mount points for example), etc..

For the windshield, was it ever replaced? Could they have messed up the install and water is now seeping into the Monty through there?

Same question for your roof rack? Were the bolts attaching it ever removed or loosened?

On my gen I, I had a leak coming in on my windshield. Fixed it when I had to replace it (all that would ever get wet was the carpet and it was fairly minor so I wasn't too concerned).

Good luck with that and let us know where you find the leak. <img src="/forums/images/graemlins/kewl.gif" alt="" />