Concerning the SX-4 gas tank: Gas tanks for all Eagle are interchangable, EXCEPT, (you guessed it) the SX-4. All other Eagles have a 22 gallon tank, with the gas gauge float in the top of the tank. The SX-4 has a 21 gallon tank, with the gauge located in the front, passenger side of the tank. But, (and the good news is) I think the gas tank from a Spirit hatchback is the same as the SX-4, since they are the same body style. The Spirit sedan may be different, since the body lines are similar to an Eagle Kammback, or a Gremlin.This should increase your chances of getting a new tank.