I have had to add Freon to my 2008 X5 4.8L every year since 2012. Every spring it is low and I have cold drivers seat and warm vents elsewhere. Add a little Freon till the pass side is cold and I have been good till next year.

I actually replaced all the Orings that are accessable in the engine compartment except for the connection to the firewall.
Has anyone pulled that connection apart to inspect/replace Orings? I wonder if that is the source of the very slow leak. I can add Freon in about 45 minutes each year but it should not be leaking.