Mazda 3 - Water leak in the boot - please help

[Horrgakx]

Hi all - my wife's 2003 Mazda 3 has a water leak in the boot.  Quite a lot of water is getting in there.  I've checked the rubbers around the boot and they're all fine.  It fills with water just sat on the drive so I know it's not coming up through any holes etc. 
The prime suspect for me is where the rear wiper enters the glass on the boot lid.  I don't know if there should be a grommet to seal it, but the arm just goes straight in through the glass.

This is a photo of where the arm goes through the glass - should there be a grommet? (link the photo, the upload folder is full apparently)
https://imgur.com/a/huRQ2yn

[StevenRB45]

There's no rubber grommet on the outside the seal inside can perish.

Also check the reversing lights and fog lights, the seals around these can fail and allow water ingress.