Water pours into my trunk after opening after a heavy rain. How to repair this?

I looked it up and didn't see any bulletins about trunk leaks. Maybe it was in a rear collision accident at one time? The only possible way to find the leak is to have someone in trunk with a bright light and then use a garden hose to soak the car down. We tried this a few times and it didn't work for small leaks. When it rains it would leak but not with a garden hose. If you can find someone brave enough,someone in trunk while going through car wash. A bright light and maybe ware a rain coat because they will most likely get soaked. We never tried that yet:)

I have a 2010 Dodge Avenger with the same issue when i went back to the dealership they told me that is the only hiccup with the car

Yes im let me know what they say

I have the 2010 avenger also leaks in the trunk after it rains. no resolution. Also have major electronic issues