turns over but won't start..

Sounds like A cam-position sensors or crank position sensors . You do have gas Wright ?

Tricia Tumele could be a fuel or spark issue. You changed the spark plugs but need to check the coils as well. Remember that the 04/04 RX 8 had a TPB about using different plugs then listed in the manual. Make sure your replacement reflects that. It also is having chronic issues with flooding which can get the catalytic converter to clog and fail. Have that checked too. As for possible fuel issues you need to check the relay, the fuses, and the pump itself. This is a great car but needs a lot of personal attention. Here is the troubleshooting guide from the manual which may help out. It’s a ‘05 which works for the ‘04 as well. 2005 RX8 EngineProblem

Turning over means the starter is good. Turn the key to ON without starting it, and should hear a bit of noise from the fuel pump turning on then off. If not, could be the engine isn’t getting any fuel. To test further, disconnect a fuel line, and have someone turn the key to On momentarily and see if fuel spurts out. If not, then it’s likely the fuel pump, which is in the fuel tank…