Gas Smells and Fuel Leaks...

The RX-8 is know for fuel leaks. Fortunately, it is almost always has to do with the fuel pump. Unfortunately, when the leak is from the top cover for the fuel pump it comes as an entire fuel pump assembly. You need to determine if the pump cover is leaking around the large seal that holds it to the tank, or if the pump-outlet-tube is cracked.

With the left rear seat base, and the metal inspection cover removed, you will likely see and smell gas. If it is a cracked outlet tube, there will be a hairline crack down it's length. It typically appears on the bottom side of the tube and will be visible with the fuel line still attached. A small mirror can help you see it. If you don't see it, start the engine and look for it dripping. It should be really obvious. If not, the problem lies with the seal between the tank, and the tank cover. Often, when the fuel pump is replaced, the big plastic nut that holds it down will not be adequately tightened. Sometimes, that plastic nut will crack on it's side when it gets old. A careful inspection should reveal your troubles.