Congrats on picking up the Caddy. I guess it depends on what you have in the cargo area. If you are carrying stuff that has a strong odour or gives of fumes (eg paint/solvent/thinners) then you probably want the vapour barrier to remain airtight. I have seen vapour barriers with clear acrylic windows installed (as in properly installed with a seal around the edge) which would allow you to see through the barrier but maintain the airtight separation between the cargo area and the cabin. If this is not an issue then a dremel, a cutting bit, a drill, a piece of acrylic and some nuts, bolts and washers should do the trick.
Another option is to fit a reversing camera. One of the things that I want to do to my Caddy Life is to install a reversing camera because even with nice big wing mirrors and the central rear view mirror there is a big blindspot directly behind the Caddy, below the level of the rear window that you just have to guess that there are no kiddies or bollards lurking there. They are not too expensive but I want to save up to get the OEM RCD510 head unit and an OEM reversing camera so it is all integrated nicely into the dash with a decent sized screen to view.
Bookmarks