I have no experience fixing a rear door leak but my thoughts are that the weather stripping might help but probably only as a temporary fix. Summer heat might make it not stick well after a while.
If it were mine, I see if the door or latch or hinges could be adjusted to make a tighter seal. Check the door seal rubber to see if it is torn or loose. That's a heavy door.... it may have sagged a bit leaving a gap at the top.
Stop by some auto wreckers yards on your travels and see if you can get a replacement rubber door seal.
One of my side compartments leaked a little. I adjusted the lock and the latch to make it close tighter. That solved the problem.
Rear Door Leaking
Linear Mode
