Big C,
Many Vipers leak. What you describe is most likely the windshield below the plastic windshield cowling. You can seal this with silicone RTV.
If the side windows are leaking this would be obvious, you get water in the seat. Have someone sit in there and try to make them wet with a garden hose. Most Vipers will leak with a pressure hose against the side windows.
If your windshield is leaking, it will drip from the removable knee bolster under the dash. There is so much crap up under there that it is hard to see. Usually it will be wet in the center of the carpet and towards the side sill. Very common.
The other place Vipers leak is in the door speaker. Behind the door panel is plastic sheeting. If your door panels have been off or aftermarket speakers in place, then the plastic may have been cut and water is actually coming in from behind the door panel. If this is the case then it will be wet primarily near the side sill.