Fuel smell through heater and ac - 1999 Dodge Intrepid

Agreed with Scot there, bet there is a leak in a fuel line under the hood somewhere. Obvious first places to check are where the lines come up by the firewall just in front of the cab. Other spots I'd check are all over the top of the engine since that is the closest place to the ventilation intake. Also just to be thurough take a close look at all the lines that run all the way under the car because it might be gettint into the ventilator some other way.
One other thought, are you certain it is fuel? Any other automotive fluids it could be, for instance WE40 that might have been used on the vent doors or wiper arms? Maybe there could also be a leaky bottle of fuel treatment lost under the dash? Good luck with that.

YOU MOST LIKLY HAVE A LEAK UNDER THE HOOD AND SMELL IS COMMING THROUGH COWL VENT SHOULD HAVE LEAK CHECKED RIGHT AWAY