So I just went and gave it a shot. It works.
I took apart my console and cut a hole thru the back of the box and the front of the rear air duct. I kept the square I cut out to cover the hole when I'm not using it as a fridge.
AC on high, all vents open- 50°F after 5 mins.
AC on high, vents closed- 40° after 5 mins.
Tomorrow I will add foam tape to seal the lid better and get pics posted.