Originally Posted by wpoll

The search issue is easy. Don't use the Xoutpost search - it's not great. Use Google with the "site:" command. Enter a search term like this: -

site:xoutpost.com e53 rear seat vent always hot

While this search is bound to be better than anything Xoutpost turns up, in this case there's still not a lot of useful results!

If the rear air stratification control is set to cool (blue dot) and you are still getting hot air from the rear vent, you might want to check the flap control in the vent housing is working.