Are there ANY indications of fuel dripping on the ground? If so, that makes it easier.
If not, remove the fuel pump cover (bottom of the fuel tank at the back, remove the 2 10mm nuts and washers and slide the bottom out of the fuel tank cradle)
Check the fuel pump and filter connection carefully.
While under there, look for any indication around the frame where the fuel tank vent tube goes through the frame. Those vent hoses are really bad about cracking and leaking.
If no leaks are detected there, move to the top of the tank. Inside the hatch and under the carpet on the right side as you look from the back of the car is a fiber patch which covers the access to the fuel tank sensor. The sensor is held in place by a large plastic "nut." There is a seal under the sensor that might not be sealing. Any indications of leaking fuel there?
The sensor and the seal "snap" into place and the large plastic "nut" holds everything in place. If the sensor is not "snapped" down, it will leak.
Last place to check is the vent line up by the neck of the tank. You will have to remove the large spring "circlip" that holds the flap into place and look down past the fill hole to see the vent connection. One or both of the hoses could have cracks or be disconnected or just loose at the connection.
If there are no leaks at any of these locations, check the tank for a small pinhole or crack.
Good Luck!
