i had the same problem. what i did to fix was simple. it came with water in the trunk when i bought it. first thing to replace is the gasket aroound the tailights. secondly if you have the trim water can leak through there. i fixed the lights but i still had some water come in when it rained. so i simply went into the trunk and put hot glue on each spot where the trim is plugged into. i no longer have leaks. Oh yea check for the fender rust. it might be a good idea to fix that.