Has this car been involved in any type of accident that may have caused the trunk lid to be forced away from the seal. It doesn’t take much of a hit and it’s sometimes impossible to see the mis-match. Unless the seal became chewed up from something…or forced open when frozen…and the seal is damaged, they normally can be adjusted.
My sister was getting water into the trunk after a accident. All that the body shop had to fix was replacing the bumper. When she noticed the water in the spare tire well she took it back and the body shop told her they could do nothing.
I suppose because the case with the insurance company was closed and the body shop would have to foot the bill.
She brought it to me and I had to pull the back seats and moulding out to get at the hinges, but I got them adjusted. I recently had to change out a tire for her and it is still dry by the spare after two years.