92 Grand Marquis gas leak?

I have a 92 Grand Marquis and it is leaking fuel in the area of the middle of the back seat just in front of the rear axle. It seems to leak constantly but REALLY leaks when the car is running. Any suggestions?
Thanks!

Since it's worse when the car is running, that may indicate that it's somewhere after the fuel pump and not the tank itself. Get some good anti-liquid goggles and some bright light and see where it's leaking from.