Carrier/rack problems of the 1997 Dodge Neon

Spare tire cavity was full of water. This caused the spare to be rusted as well as the floor under the tire and the jack. I have never had to use the spare so I dont know how long the water has been there. From the amount that was in there, I would say it has collected every rain drop since I have had the car. This caused me to have my car towed instead of being able to use the spare. This could have been very bad if I had been in a rural area or if I had no car phone. If there's anything you can do, please let me know. A rear taillight was replaced under warranty when I first got the car due to water intrusion. Maybe this is what caused the problem.