It rained here for like a week and I found that the spare tire compartment was full of water.
Does anyone know where the leak is coming from?

I tried to run the hose over the trunk and see if i can locate it but there was not sign of any leaks.

 

take out your spare tire and see if there any open hole.. i know once i had it open it came in.

 

Check to see if any other parts of the trunk are wet because then that could lead you to the leak.

 

leaking tail lights are a major culprit. I know mine do. I have got to fix that. In the mean time, put your tools in zip lock bags to keep the rust away.

 

Yes, it's the tail light gasket, change it out or apply some sealant, like i did and that stopped it.

 

in the bottom of the spare tire well there should be a plug grimit, pull that out and it will drain any free standing water out of the trunk